A naive Bayesian classifier (NBC) combined with principal component analysis (PCA) effectively differentiates the dose-dependent effects of certain groups of psychoactive drugs based on their impact on the amplitude-spectral characteristics of electrocorticograms (ECoG) in rats. This approach has been shown to be useful for pharmacological screening of agents with unknown or poorly understood activity. Despite previously obtained optimistic results, classification determination for some drugs was inaccurate, necessitating the search for possible ways to improve the predictive effectiveness of the proposed algorithm. One possible approach would be to use as input quantitative data not only the impact of the psychoactive drugs studied on the amplitude-spectral characteristics of ECoG but also connectivity changes, including the average coherence power of different pairs of leads. The aim of this study was to compare the accuracy of NBC in classifying the pharmacological mechanism of action of agents with well-known mechanisms (test set) using pharmaco-EEG data on changes in the amplitude-spectral characteristics of ECoG, coherence, and the combined use of two data sets. Materials and methods. Experiments were performed on Wistar rats with chronically implanted ECoG electrodes. The training set, relative to which the effects of the pharmacological agents from the test set were classified, were the matrices of effects of 12 pharmacological agents: the NMDA antagonist dizocilpine, the D2/D3 antagonists haloperidol and sulpiride, the M-anticholinergic tropicamide, the H1/5HT2A receptor blocker hydroxyzine, the acetylcholinesterase inhibitor galantamine, the alpha-2 adrenergic agonist dexmedetomidine, the alpha-2 adrenergic antagonist atipamezole, the adenosine receptor blocker caffeine and the GABA-mimetics aminophenylbutyric acid (phenibut), bromdihydrochlorophenylbenzodiazepine (phenazepam) and 5-ethyl-5-phenyl-2,4,6(1H,3H,5H)-pyrimidinetrione. The test set included various drugs with tropism for the targets of the training set drugs: dopamine receptor antagonists chlorpromazine, droperidol, tiapride and raclopride, H1-histamine blockers diphenhydramine and promethazine, 5-HT2-receptor blockers ritanserin and glemenserin, acetylcholinesterase inhibitor ipidacrine, alpha2-adrenergic receptor antagonist yohimbine, alpha2-adrenergic agonists medetomidine and xylazine, GABA-mimetics 5-ethyl-5-(1-methylbutyl)-2,4,6(1H,3H,5H)-pyrimidinetrione and chloral hydrate. The analysis of the ECoG signal included the calculation of 132 amplitude-spectral characteristics and 75 coherence indicators, which, using the PCA, led to new integrative indicators used for further classification of the NBC. Results and discussion. For each drug in the test set, the median similarity probability with a particular group from the training set was calculated, which was used to assess the classification quality. It was found that, when using the amplitude-spectral characteristics of ECoG, the proposed methodological approach allows for the identification of the ECoG effects of several groups of psychoactive drugs, including D2/D3-dopamine, M-cholinergic, H1-histamine, and 5-HT2-serotonin receptor blockers, AChE inhibitors, GABA-mimetics, and alpha-2-adrenergic receptor agonists and antagonists. This approach enabled the correct classification of 18 of 24 groups in the test set. When using changes in coherence indices as the initial data, the classification accuracy also amounted to 18 of 24 groups. When combining the two data sets, the number of correctly identified NBC groups was 20 of 24 groups. When comparing the classification during training (confusion matrix), it was found that coherence data or adding coherence data to the data based on changes in amplitude-spectral characteristics leads to a statistically significant (p < 0.01 in both cases) increase in accuracy. Conclusions. The obtained data demonstrated high accuracy in classifying the pharmacological activity of the test sample drugs using any of the three compared approaches. Despite the lack of statistically significant differences between them, classification based on the combined dataset demonstrated a higher number of "correct" similarities. This allows us to recommend the approach based on combined data of drug effects on amplitude-spectral characteristics and coherence as the most promising for further studies using pharmaco-EEG screening.

General anesthetics enable invasive experimentation but can affect cardiovascular and respiratory physiology, biasing preclinical outcomes. We compared five anesthetic regimens in adult male Wistar rats, tribromoethanol (TBE, 250 mg/kg i.p.), chloral hydrate (CH, 400 mg/kg i.p.), ketamine-xylazine (KX, 80/10 mg/kg i.p.), thiopental (TP, 80 mg/kg i.p.), and isoflurane (ISO, 4% induction, 2% maintenance), to investigate integrated cardiorespiratory and biochemical markers. Femoral arterial catheterization allowed continuous blood pressure (BP) and derived heart rate (HR) recordings, while ventilation was assessed through pletysmography at baseline (awake), during induction, and early recovery phases of anesthesia. Variability was evaluated in the time and frequency domains, including HR, systolic blood pressure (SBP), and spontaneous baroreflex sensitivity. In an independent cohort of rats, butyrylcholinesterase (BChE), CK-MB, cTnI, and LDH were measured. Baseline BP was unchanged by TBE and TP, whereas all anesthetics affected HR. Minute ventilation and breathing frequency were reduced with all agents, while tidal volume decreased with KX and TBE only. LDH and cTnI were unaffected, BChE was reduced by KX, TBE, and ISO, and CK-MB increased with CH and KX. Variability analysis showed that all anesthetics depressed pulse-interval and SBP variability and shifted spectral power toward higher frequencies, while baroreflex sensitivity and effectiveness were consistently reduced. During early recovery, KX and TP restored most variability indices, whereas CH, TBE, and ISO showed continued suppression of these indices. These findings highlight distinct profiles of cardiovascular depression and biomarker responses across anesthetics and underscore the importance of accounting for autonomic variability when selecting different anesthetics in experimental protocols.

Cadaver-based anatomy teaching relies on preservation systems that allow donated bodies to remain usable across repeated teaching sessions. Formaldehyde exposure in dissection facilities has been studied extensively, yet the upstream environmental burden associated with long-term cadaver pool maintenance solutions has received much less attention. In this screening cradle-to-gate life cycle assessment, three pool formulations were compared: Kinnamon storage solution, Original Larssen solution, and Modified Larssen solution. Institutional recipe data were converted into component masses, and cradle-to-gate emission factors were assigned from available life cycle inventory sources or, where no direct match was available, from explicitly labeled chemical-category proxies. The main result was expressed per kilogram of prepared mixture; the volume-based value was retained only as an auxiliary indicator per liquid input volume. In the baseline model, Modified Larssen had the lowest mass-normalized GWP100 value (0.510 kg CO2e/kg), followed by Kinnamon storage solution (0.665 kg CO2e/kg) and Original Larssen solution (0.699 kg CO2e/kg). The leading hotspots were glycerin or glycerol in the Kinnamon and Modified Larssen formulations, and chloral hydrate in the Original Larssen formulation. Thus, the modeled climate burden was not explained by formaldehyde content alone. Because toxicity, occupational exposure, service life, wastewater treatment, and disposal were not included in the quantitative boundary, these results should be interpreted as a screening inventory for reformulation priorities, not as a complete sustainability ranking.

Background/Objectives: The study was aiming to determine the test-retest repeatability of DEX or CH as single sedative agents on ABR indices by analyzing data from initial test and retest. We also preliminarily explored the correlation between sleep deprivation and onset time of sedation in group DEX and group CH, respectively. Methods: We collected data from two groups of children sedated with either DEX (n = 20, 40 ears) or CH (n = 20, 40 ears). Paired- samples t-tests and Bland-Altman plots were used to evaluate repeatability between the initial test and retest. Pearson correlation analysis was used to measure the relationship between the average onset time of sedation and the average duration of sleep deprivation in both groups. Results: Within each sedative group, no significant differences were observed in ABR indices between the initial test and retest. Additionally, in group DEX, the mean onset time was 12.15 ± 4.40 min and the mean sleep deprivation duration was 442.80 ± 85.91 min, with no correlation between them (r = 0.01, p = 0.96). In group CH, the mean onset time was 27.55 ± 15.70 min and the mean sleep deprivation duration was 455.10 ± 90.94 min, showing a significant negative correlation (r = -0.97, p = 0.00). Conclusions: ABR indices exhibited high repeatability when DEX and CH were used as a sedative in pediatric ABR examinations. The choice of sedative agent in clinical practice should be individualized, taking into account institutional protocols and clinical requirements.

Photochemical processing dictates the molecular evolution of dissolved organic matter (DOM) in sunlit waters and its subsequent reactivity during chlorination. However, how source-specific molecular signatures regulate the photochemical transformations of DOM and its associated disinfection by-product (DBP) formation potentials remains poorly understood. Here, DOM samples derived from algae (ADOM), soil (SDOM), litter (LDOM), and wildfire ash (BDOM) were exposed to 28 days of simulated solar irradiation to elucidate source-dependent molecular transformations and their impacts on specific DBP formation. DOM compositional changes were characterized using optical spectroscopy and Fourier transform-ion cyclotron resonance mass spectrometry, and specific DBP formation potentials were assessed via chlorination assays. Distinct molecular signatures differentiated DOM sources, with ADOM enriched in protein- and lipid-like compounds, whereas SDOM, LDOM, and BDOM contained greater proportions of aromatic, lignin-, and tannin-like molecules. Irradiation drove partial convergence of DOM toward a more oxidized state, lower molecular weight, and more aromatic structures via decarboxylation, dealkylation, and deamination. These transformations reduced specific carbonaceous DBP formation (up to 93 %) across most DOM sources, whereas LDOM showed a ∼9 % increase in specific trihalomethane and chloral hydrate formation, likely due to the persistence and transformation of lignin-like precursors. Notably, specific haloacetonitrile formation potentials substantially increased by 99-125 % across all DOM sources, associated with the generation of reactive nitrogenous precursors through photo-oxidation and depolymerization of macromolecules. These findings demonstrate that solar-driven DOM transformation governs distinct carbonaceous and nitrogenous DBP responses, highlighting the need for source-specific molecular insights to predict and manage DBP risks in watersheds.

[This corrects the article on p. 82 in vol. 16, PMID: 35261594.].

[This corrects the article DOI: 10.3389/fnmol.2022.934167.].