TIAP: an observational procedure for assessing family relationships: a clinical case from the parenting evaluation context.

TIAP is an observational procedure to assess family functioning detecting simultaneously the role of each participant and the interdependence of relational behaviors. In particular, the procedure requires family members to play according to different interactive configurations (parent1-children; parent2-children, all together, children and parents as separate units) and therefore different microtransitions from one configuration to another. As such, the procedure allows to study how family members coordinate to maintain stability, promote change, and encourage members to explore different interactive configurations within the family system. TIAP has been validated through several studies conducted with different non-clinical groups of families that have highlighted the salient aspects of family functioning, and significant correlations with variables external to the family system, such as children's social-emotional competence in the educational context. This paper focuses on the use of TIAP in the contexts of assessing parental competence. Specifically, the article aims to describe, through the reference to a clinical case, the results emerged from a study conducted with 33 families involved in a parenting assessment process. The study is part of a broader collaborative project between the Child and Adolescent Neuropsychiatry Clinic of the Italian National Health Service in Parma, the University of Parma, and the Bologna Family Therapy Center. TIAP was administered to all the families involved as a complement to other tools routinely used for all cases handled by the professionals of the clinic. The coding system includes different indices. Some analyze the interactive family modes: family coordination (mutual attention and responsiveness), the responses to potentials for change (disregard, absorption, amplification), and intra-familiar exploration. Other indices concern the quality of the interactions: the relational triadic dynamic of microtransition (detaching-entrusting-welcoming-joining) and the consistency/inconsistency of the communication channels. The results highlighted how TIAP makes it possible to identify the specific interactive modalities of the different members and their interdependence and reciprocity, favoring the identification of both family weaknesses and family resources, including the children's contribution. Furthermore, the general data trend showed that TIAP indices detect some important prognostic elements capable of guiding the court's decisions.

An emerging terpolymeric nanoparticle pore former as an internal recrystallization inhibitor of celecoxib in controlled release amorphous solid dispersion beads: Experimental studies and molecular dynamics analysis.

Solid oral controlled release formulations feature numerous clinical advantages for drug candidates with adequate solubility and dissolution rate. However, most new chemical entities exhibit poor water solubility, and hence are exempt from such benefits. Although combining drug amorphization with controlled release formulation is promising to elevate drug solubility, like other supersaturating systems, the problem of drug recrystallization has yet to be resolved, particularly within the dosage form. Here, we explored the potential of an emerging, non-leachable terpolymer nanoparticle (TPN) pore former as an internal recrystallization inhibitor within controlled release amorphous solid dispersion (CRASD) beads comprising a poorly soluble drug (celecoxib) reservoir and insoluble polymer (ethylcellulose) membrane. Compared to conventional pore former, polyvinylpyrrolidone (PVP), TPN-containing membranes exhibited superior structural integrity, less crystal formation at the CRASD bead surface, and greater extent of celecoxib release. All-atom molecular dynamics analyses revealed that in the presence of TPN, intra-molecular bonding, crystal formation tendency, diffusion coefficient, and molecular flexibility of celecoxib were reduced, while intermolecular H-bonding was increased as compared to PVP. This work suggests that selection of a pore former that promotes prolonged molecular separation within a nanoporous controlled release membrane structure may serve as an effective strategy to enhance amorphicity preservation inside CRASD.

Mechanisms of complex regional pain syndrome.

Complex Regional Pain Syndrome (CRPS) is a chronic pain disorder characterized by a diverse array of symptoms, including pain that is disproportionate to the initial triggering event, accompanied by autonomic, sensory, motor, and sudomotor disturbances. The primary pathology of both types of CRPS (Type I, also known as reflex sympathetic dystrophy, RSD; Type II, also known as causalgia) is featured by allodynia, edema, changes in skin color and temperature, and dystrophy, predominantly affecting extremities. Recent studies started to unravel the complex pathogenic mechanisms of CRPS, particularly from an autoimmune and neuroimmune interaction perspective. CRPS is now recognized as a systemic disease that stems from a complex interplay of inflammatory, immunologic, neurogenic, genetic, and psychologic factors. The relative contributions of these factors may vary among patients and even within a single patient over time. Key mechanisms underlying clinical manifestations include peripheral and central sensitization, sympathetic dysregulation, and alterations in somatosensory processing. Enhanced understanding of the mechanisms of CRPS is crucial for the development of effective therapeutic interventions. While our mechanistic understanding of CRPS remains incomplete, this article updates recent research advancements and sheds light on the etiology, pathogenesis, and molecular underpinnings of CRPS.

Therapeutic drug monitoring of antiretroviral therapy: current progresses and future directions.

INTRODUCTION: The treatment of HIV infection has been revolutionized in recent years thanks to the advent of dual antiretroviral regimens, administered orally or as long-acting injectable formulations. Here, we provide an update on the usefulness of therapeutic drug monitoring (TDM) of antiretroviral drugs to optimize the management of people with HIV (PWH) in the current scenario. AREAS COVERED: A MEDLINE PubMed search for articles published between January 2014 and January 2024 was completed matching the terms HIV, antiretrovirals and TDM. Moreover, additional studies were identified from the reference list of retrieved articles. EXPERT OPINION: Available antiretroviral treatments achieve a response rate of 90%-95%, making the routine TDM of antiretroviral drugs of limited clinical value. However, there are still some important applications of TDM in selected clinical conditions, such as assessing patient compliance or suspected drug-drug interactions (DDIs). Indeed, we are increasingly having to deal with polypharmacy and DDIs in the context of an aging patient with comorbidities that may potentially alter the pharmacokinetics of antiretroviral drugs. Finally, the role of pharmacogenetics, which is closely related to TDM, in influencing both the disposition of antiretrovirals and the course of DDIs should also be considered.

A multifaceted crosstalk between brassinosteroid and gibberellin regulates the resistance of cucumber to Phytophthora melonis.

Cucumber plants are highly susceptible to the hemibiotroph oomycete Phytophthora melonis. However, the mechanism of resistance to cucumber blight remains poorly understood. Here, we demonstrated that cucumber plants with impairment in the biosynthesis of brassinosteroids (BRs) or gibberellins (GAs) were more susceptible to P. melonis. By contrast, increasing levels of endogenous BRs or exogenously application of 24-epibrassinolide enhanced the resistance of cucumber plants against P. melonis. Furthermore, we found that both knockout and overexpression of the BR biosynthesis gene CYP85A1 reduced the endogenous GA3 content compared with that of wild-type plants under the condition of inoculation with P. melonis, and the enhancement of disease resistance conferred by BR was inhibited in plants with silencing of the GA biosynthetic gene GA20ox1 or KAO. Together, these findings suggest that GA homeostasis is an essential factor mediating BRs-induced disease resistance. Moreover, BZR6, a key regulator of BR signaling, was found to physically interact with GA20ox1, thereby suppressing its transcription. Silencing of BZR6 promoted endogenous GA biosynthesis and compromised GA-mediated resistance. These findings reveal multifaceted crosstalk between BR and GA in response to pathogen infection, which can provide a new approach for genetically controlling P. melonis damage in cucumber production.

Exploration of the Binding Determinants of Protein Phosphatase 5 (PP5) Reveals a Chaperone-Independent Activation Mechanism.

The protein phosphatase 5 (PP5) is normally recruited to its substrates by the molecular chaperones, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90). This interaction requires the tetratricopeptide repeat (TPR) domain of PP5, which binds to an EEVD motif at the extreme C-termini of cytosolic Hsp70 and Hsp90 isoforms. In addition to bringing PP5 into proximity with chaperone-bound substrates, this interaction also relieves auto-inhibition in PP5's catalytic domain, promoting its phosphatase activity. To better understand the molecular determinants of this process, we screened a large, pentapeptide library for binding to PP5. This screen identified the amino acid preferences at each position, which we validated by showing that the optimal sequences bind 4- to 7-fold tighter than the natural EEVD motifs and stimulate PP5's enzymatic activity. The enhanced affinity for PP5's TPR domain was confirmed using a protein-adaptive differential scanning fluorimetry (paDSF) assay. Using this increased knowledge of structure-activity relationships, we re-examined affinity proteomics results to look for potential EEVD-like motifs in the C-termini of known PP5-binding partners. This search identified elongator acetyltransferase complex subunit 1 (ELP1/IKBKAP) as a putative partner and, indeed, we found that its C-terminal sequence, LSLLD, binds directly to PP5's TPR domain in vitro. Consistent with this idea, mutation of ELP1's terminal aspartate was sufficient to interrupt the interaction with PP5 in vitro and in cells. Together, these findings reveal the sequence preferences of PP5's TPR domain and expand the scope of PP5's functions to include chaperone-independent complexes.

Forebrain commissure formation in zebrafish embryo requires the binding of KLC1 to CRMP2.

Formation of the corpus callosum (CC), anterior commissure (AC), and postoptic commissure (POC), connecting the left and right cerebral hemispheres, is crucial for cerebral functioning. Collapsin response mediator protein 2 (CRMP2) has been suggested to be associated with the mechanisms governing this formation, based on knockout studies in mice and knockdown/knockout studies in zebrafish. Previously, we reported two cases of non-synonymous CRMP2 variants with S14R and R565C substitutions. Among the, the R565C substitution (p.R565C) was caused by the novel CRMP2 mutation c.1693C > T, and the patient presented with intellectual disability accompanied by CC hypoplasia. In this study, we demonstrate that crmp2 mRNA could rescue AC and POC formation in crmp2-knockdown zebrafish, whereas the mRNA with the R566C mutation could not. Zebrafish CRMP2 R566C corresponds to human CRMP2 R565C. Further experiments with transfected cultured cells indicated that CRMP2 with the R566C mutation could not bind to kinesin light chain 1 (KLC1). Knockdown of klc1a in zebrafish resulted in defective AC and POC formation, revealing a genetic interaction with crmp2. These findings suggest that the CRMP2 R566C mutant fails to bind to KLC1, preventing axonal elongation and leading to defective AC and POC formation in zebrafish and CC formation defects in humans. Our study highlights the importance of the interaction between CRMP2 and KLC1 in the formation of the forebrain commissures, revealing a novel mechanism associated with CRMP2 mutations underlying human neurodevelopmental abnormalities.

Synchronic distribution of the dinoflagellate Protoceratium reticulatum and yessotoxins in a high stratified fjord system: Tidal or light modulation?

Protoceratium reticulatum is the main yessotoxin-producer along the Chilean coast. Thus far, the yessotoxin levels recorded in this region have not posed a serious threat to human health. However, a bloom of P. reticulatum during the austral summer of 2022 caused the first ban of shellfish collection, due to the high toxin levels. A bloom of P. reticulatum during the austral summer of 2020 allowed an evaluation of the fine-scale distribution of the dinoflagellate during a tidal cycle. High-resolution measurements of biophysical properties were carried out in mid-summer (February 18-19) at a fixed sampling station in Puyuhuapi Fjord, Chilean Patagonia, as part of an intensive 24-h biophysical experiment to monitor the circadian distributions of P. reticulatum vegetative cells and yessotoxins. High P. reticulatum cell densities (>20 × 103 cells L-1) were found in association with a warmer (14.5-15 °C) and estuarine (23.5-24.5 g kg-1) sub-surface water layer (6-8 m). P. reticulatum cell numbers and yessotoxins followed a synchronic distribution pattern consistent with the excursions of the pycnocline. Nevertheless, the surface aggregation of the cells was modulated by the light cycle, suggesting daily vertical migration. The yessotoxin content per P. reticulatum cell ranged from 9.4 to 52.2 pg. This study demonstrates both the value of fine-scale resolution measurements of biophysical properties in a highly stratified system and the potential ecosystem impact of P. reticulatum strains producing high levels of yessotoxins.

Role and significance of virus-bacteria interactions in disease progression.

Understanding disease pathogenesis caused by bacteria/virus, from the perspective of individual pathogen has provided meaningful insights. However, as viral and bacterial counterparts might inhabit the same infection site, it becomes crucial to consider their interactions and contributions in disease onset and progression. The objective of the review is to highlight the importance of considering both viral and bacterial agents during the course of coinfection. The review provides a unique perspective on the general theme of virus bacteria interactions, which either lead to colocalized infections that are restricted to one anatomical niche, or systemic infections which have a systemic effect on the human host. The sequence, nature and underlying mechanisms of certain virus-bacteria interactions have been elaborated with relevant examples from literature. It also attempts to address the various applied aspects including diagnostic and therapeutic strategies for individual infections as well virus bacteria coinfections. The review aims to aid researchers in comprehending the intricate interplay between virus and bacteria in disease progression, thereby enhancing understanding of current methodologies and empowering the development of novel health care strategies to tackle coinfections.

Towards Development of the 4C-Based Method Detecting Interactions of Plasmid DNA with Host Genome.

Chromosome conformation capture techniques have revolutionized our understanding of chromatin architecture and dynamics at the genome-wide scale. In recent years, these methods have been applied to a diverse array of species, revealing fundamental principles of chromosomal organization. However, structural organization of the extrachromosomal entities, like viral genomes or plasmids, and their interactions with the host genome, remain relatively underexplored. In this work, we introduce an enhanced 4C-protocol tailored for probing plasmid DNA interactions. We design specific plasmid vector and optimize protocol to allow high detection rate of contacts between the plasmid and host DNA.

Potential drug-drug interactions analysis in Polish pediatric pneumonology units, including cystic fibrosis patients.

The lack of data on drug-drug interactions in pediatrics represents a relevant problem in making appropriate therapeutic decisions. Our study aimed to investigate the incidence and risk factors for potential drug-drug interactions (pDDIs) in pediatric pneumonology units, including cystic fibrosis patients. We performed a 6-month prospective observational study during which clinical pharmacists, using the Lexicomp Drug Interactions checker, screened medical records to identify pDDIs. Spearman's rank coefficient, logistic regression, and the Mann-Whitney U test were used to identify correlations, analyze risk factors for pDDIs, and compare cystic fibrosis patients with the rest, respectively. Recommendations were provided for the D and X pDDIs categories. Within the 218 patients, 428 pDDIs were identified, out of which 237 were classified as clinically significant. Almost 60% of patients were exposed to at least one relevant interaction. The number of pDDIs correlated with the number of; drugs (rs = 0.53, P <  .001), hospitalization length (rs = 0.20, P <  .01), and off-label medicines (rs = 0.25, P <  .001). According to the multivariate analysis, at least 6 administered medications (OR = 4.15; 95% CI = 2.21-7.78), 4 days of hospitalization (OR = 6.41; 95% CI = 2.29-17.97), and off-label therapy (OR = 3.37; 95% CI = 1.69-6.70) were the risk factor for pDDIs. Despite significant differences in the number of medications taken, comorbidities, and off-label drugs, cystic fibrosis patients were not more exposed to pDDI. Given the lack of data on pDDIs in the pediatric population, the need for close cooperation between clinicians and clinical pharmacists to improve the safety and efficacy of pharmacotherapy is highlighted.

The dynamics of N6-methyladenine RNA modification in resistant and susceptible rice varieties responding to rice stem borer damage.

N6-methyladenosine (m6A) is the most prevalent modification in cellular RNA which orchestrates diverse physiological and pathological processes during stress response. However, the differential m6A modifications that cope with herbivore stress in resistant and susceptible crop varieties remain unclear. Here, we found that rice stem borer (RSB) larvae grew better on indica rice (e.g., MH63, IR64, Nanjing 11) than on japonica rice varieties (e.g., Nipponbare, Zhonghua 11, Xiushui 11). Then, transcriptome-wide m6A profiling of representative resistant (Nipponbare) and susceptible (MH63) rice varieties were performed using a nanopore direct RNA sequencing approach, to reveal variety-specific m6A modifications against RSB. Upon RSB infestation, m6A methylation occurred in actively expressed genes in Nipponbare and MH63, but the number of methylation sites decreased across rice chromosomes. Integrative analysis showed that m6A methylation levels were closely associated with transcriptional regulation. Genes involved in herbivorous resistance related to mitogen-activated protein kinase, jasmonic acid (JA), and terpenoid biosynthesis pathways, as well as JA-mediated trypsin protease inhibitors, were heavily methylated by m6A, and their expression was more pronounced in RSB-infested Nipponbare than in RSB-infested MH63, which may have contributed to RSB resistance in Nipponbare. Therefore, dynamics of m6A modifications act as the main regulatory strategy for expression of genes involved in plant-insect interactions, which is attributed to differential responses of resistant and susceptible rice varieties to RSB infestation. These findings could contribute to developing molecular breeding strategies for controlling herbivorous pests.

bZIP60 and Bax inhibitor 1 contribute IRE1-dependent and independent roles to potexvirus infection.

IRE1, BI-1, and bZIP60 monitor compatible plant-potexvirus interactions though recognition of the viral TGB3 protein. This study was undertaken to elucidate the roles of three IRE1 isoforms, the bZIP60U and bZIP60S, and BI-1 roles in genetic reprogramming of cells during potexvirus infection. Experiments were performed using Arabidopsis thaliana knockout lines and Plantago asiatica mosaic virus infectious clone tagged with the green fluorescent protein gene (PlAMV-GFP). There were more PlAMV-GFP infection foci in ire1a/b, ire1c, bzip60, and bi-1 knockout than wild-type (WT) plants. Cell-to-cell movement and systemic RNA levels were greater bzip60 and bi-1 than in WT plants. Overall, these data indicate an increased susceptibility to virus infection. Transgenic overexpression of AtIRE1b or StbZIP60 in ire1a/b or bzip60 mutant background reduced virus infection foci, while StbZIP60 expression influences virus movement. Transgenic overexpression of StbZIP60 also confers endoplasmic reticulum (ER) stress resistance following tunicamycin treatment. We also show bZIP60U and TGB3 interact at the ER. This is the first demonstration of a potato bZIP transcription factor complementing genetic defects in Arabidopsis. Evidence indicates that the three IRE1 isoforms regulate the initial stages of virus replication and gene expression, while bZIP60 and BI-1 contribute separately to virus cell-to-cell and systemic movement.

Structural analysis of neomycin B and kanamycin A binding Aminoglycosides Modifying Enzymes (AME) and bacterial ribosomal RNA.

Aminoglycosides are crucial antibiotics facing challenges from bacterial resistance. This study addresses the importance of aminoglycoside modifying enzymes in the context of escalating resistance. Drawing upon over two decades of structural data in the Protein Data Bank, we focused on two key antibiotics, neomycin B and kanamycin A, to explore how the aminoglycoside structure is exploited by this family of enzymes. A systematic comparison across diverse enzymes and the RNA A-site target identified common characteristics in the recognition mode, while assessing the adaptability of neomycin B and kanamycin A in various environments.

Exploring Favorable Supramolecular Interactions of Multifluorinated Aromatics in Dendronized Push-Pull Chromophores for Electro-Optics.

Multifluorinated aromatics serve as supramolecular synthons in the research of organic electro-optic (EO) materials by exploiting π-π stacking interaction between the aromatic hydrocarbon and multifluorinated aromatic groups for performance improvement. However, non-classical hydrogen bonding remains largely unexplored in fluorinated EO dendrimers. In this study, three Fréchet-type generation 1 benzyl ether co-dendrons were synthesized by replacing one benzyl group with 2,3,5,6-tetrafluorobenzyl (p-HF4Bz), pentafluorobenzyl (C6F5Bz), and 2,3,4,5-tetrafluorobenzyl (o-HF4Bz) groups, to afford the benzoic acid derivatives D1, D2, and D3, which were further bonded to the donor and π-bridge moieties to afford three co-dendronized push-pull phenyltetraene chromophores EOD1, EOD2, and EOD3, respectively. The weak C-H⋅⋅⋅X (X = O, F) interactions in the crystal structure of D1 cumulatively add to the benzoic acid dimers to form an extended hydrogen-bonded network, while D2 is crystallized into a centric one-dimensional chain with strong intermolecular interactions. The poled films of EOD1 with PMMA exhibited the largest and most stable EO activity with optical homogeneity among the series. The results identify the effectiveness of weak but favorable hydrogen bonds enabled by the enhanced carbon acidity of p-HF4Bz synthon in D1, over the interactions in D2 and D3, for the rational design of supramolecular EO dendrimers.

Mycorrhizal associations modify tree diversity-productivity relationships across experimental tree plantations.

Decades of studies have demonstrated links between biodiversity and ecosystem functioning, yet the generality of the relationships and the underlying mechanisms remain unclear, especially for forest ecosystems. Using 11 tree-diversity experiments, we tested tree species richness-community productivity relationships and the role of arbuscular (AM) or ectomycorrhizal (ECM) fungal-associated tree species in these relationships. Tree species richness had a positive effect on community productivity across experiments, modified by the diversity of tree mycorrhizal associations. In communities with both AM and ECM trees, species richness showed positive effects on community productivity, which could have resulted from complementarity between AM and ECM trees. Moreover, both AM and ECM trees were more productive in mixed communities with both AM and ECM trees than in communities assembled by their own mycorrhizal type of trees. In communities containing only ECM trees, species richness had a significant positive effect on productivity, whereas species richness did not show any significant effects on productivity in communities containing only AM trees. Our study provides novel explanations for variations in diversity-productivity relationships by suggesting that tree-mycorrhiza interactions can shape productivity in mixed-species forest ecosystems.

From X-ray crystallographic structure to intrinsic thermodynamics of protein-ligand binding using carbonic anhydrase isozymes as a model system.

Carbonic anhydrase (CA) was among the first proteins whose X-ray crystal structure was solved to atomic resolution. CA proteins have essentially the same fold and similar active centers that differ in only several amino acids. Primary sulfonamides are well defined, strong and specific binders of CA. However, minor variations in chemical structure can significantly alter their binding properties. Over 1000 sulfonamides have been designed, synthesized and evaluated to understand the correlations between the structure and thermodynamics of their binding to the human CA isozyme family. Compound binding was determined by several binding assays: fluorescence-based thermal shift assay, stopped-flow enzyme activity inhibition assay, isothermal titration calorimetry and competition assay for enzyme expressed on cancer cell surfaces. All assays have advantages and limitations but are necessary for deeper characterization of these protein-ligand interactions. Here, the concept and importance of intrinsic binding thermodynamics is emphasized and the role of structure-thermodynamics correlations for the novel inhibitors of CA IX is discussed - an isozyme that is overexpressed in solid hypoxic tumors, and thus these inhibitors may serve as anticancer drugs. The abundant structural and thermodynamic data are assembled into the Protein-Ligand Binding Database to understand general protein-ligand recognition principles that could be used in drug discovery.

Microbial diversity, genomics, and phage-host interactions of cyanobacterial harmful algal blooms.

The occurrence of cyanobacterial harmful algal blooms (cyanoHABs) is related to their physical and chemical environment. However, less is known about their associated microbial interactions and processes. In this study, cyanoHABs were analyzed as a microbial ecosystem, using 1 year of 16S rRNA sequencing and 70 metagenomes collected during the bloom season from Lake Okeechobee (Florida, USA). Biogeographical patterns observed in microbial community composition and function reflected ecological zones distinct in their physical and chemical parameters that resulted in bloom "hotspots" near major lake inflows. Changes in relative abundances of taxa within multiple phyla followed increasing bloom severity. Functional pathways that correlated with increasing bloom severity encoded organic nitrogen and phosphorus utilization, storage of nutrients, exchange of genetic material, phage defense, and protection against oxidative stress, suggesting that microbial interactions may promote cyanoHAB resilience. Cyanobacterial communities were highly diverse, with picocyanobacteria ubiquitous and oftentimes most abundant, especially in the absence of blooms. The identification of novel bloom-forming cyanobacteria and genomic comparisons indicated a functionally diverse cyanobacterial community with differences in its capability to store nitrogen using cyanophycin and to defend against phage using CRISPR and restriction-modification systems. Considering blooms in the context of a microbial ecosystem and their interactions in nature, physiologies and interactions supporting the proliferation and stability of cyanoHABs are proposed, including a role for phage infection of picocyanobacteria. This study displayed the power of "-omics" to reveal important biological processes that could support the effective management and prediction of cyanoHABs. IMPORTANCE: Cyanobacterial harmful algal blooms pose a significant threat to aquatic ecosystems and human health. Although physical and chemical conditions in aquatic systems that facilitate bloom development are well studied, there are fundamental gaps in the biological understanding of the microbial ecosystem that makes a cyanobacterial bloom. High-throughput sequencing was used to determine the drivers of cyanobacteria blooms in nature. Multiple functions and interactions important to consider in cyanobacterial bloom ecology were identified. The microbial biodiversity of blooms revealed microbial functions, genomic characteristics, and interactions between cyanobacterial populations that could be involved in bloom stability and more coherently define cyanobacteria blooms. Our results highlight the importance of considering cyanobacterial blooms as a microbial ecosystem to predict, prevent, and mitigate them.

Effect of carvedilol on pharmacokinetics of sofosbuvir and its metabolite GS-331007: role of P-glycoprotein.

Sofosbuvir (SOF) is a P-glycoprotein (P-gp) substrate, and carvedilol (CAR) is an inhibitor of P-gp, suggesting that it may affect the oral pharmacokinetics and safety of SOF. The current study investigated the pharmacokinetic interaction of CAR with SOF and its metabolite, GS-331007, and the possible consequent toxicities in rats. To assess the pharmacokinetics of SOF and GS-331007, rats were divided into three groups; all received a single oral dose of SOF preceded with saline (SAL), verapamil (VER) as a standard P-gp inhibitor, or CAR, respectively. The serosal, plasma, and hepatic tissue contents of SOF and GS-331007 were assessed using LC-MS/MS. Renal and hepatic toxicities were assessed using biochemical and histopathological tests. Serosal and plasma concentrations of SOF and GS-331007 were increased in the presence of CAR, suggesting a significant inhibitory effect of CAR on intestinal P-gp. Simultaneously, the pharmacokinetic profile of SOF showed a significant increase in the Cmax, AUC(0-t), AUC (0-∞), t1/2, and a reduction in its apparent oral clearance. While the pharmacokinetic profile of GS-331007 was not significantly affected. However, this notable elevation in drug oral bioavailability was corroborated by a significant alteration in renal functions. Hence, further clinical investigations are recommended to ensure the safety and dosing of CAR/SOF combination.

Interactions of binary mixtures of metals on rainbow trout (Oncorhynchus mykiss) heart mitochondrial H2O2 homeodynamics.

For continuous pumping of blood, the heart needs a constant supply of energy (ATP) that is primarily met via oxidative phosphorylation in the mitochondria of cardiomyocytes. However, sustained high rates of electron transport for energy conversion redox reactions predisposes the heart to the production of reactive oxygen species (ROS) and oxidative stress. Mitochondrial ROS are fundamental drivers of responses to environmental stressors including metals but knowledge of how combinations of metals alter mitochondrial ROS homeodynamics remains sparse. We explored the effects and interactions of binary mixtures of copper (Cu), cadmium (Cd), and zinc (Zn), metals that are common contaminants of aquatic systems, on ROS (hydrogen peroxide, H2O2) homeodynamics in rainbow trout (Oncorhynchus mykiss) heart mitochondria. Isolated mitochondria were energized with glutamate-malate or succinate and exposed to a range of concentrations of the metals singly and in equimolar binary concentrations. Speciation analysis revealed that Cu was highly complexed by glutamate or Tris resulting in Cu2+ concentrations in the picomolar to nanomolar range. The concentration of Cd2+ was 7.2-7.5 % of the total while Zn2+ was 15 % and 21 % of the total during glutamate-malate and succinate oxidation, respectively. The concentration-effect relationships for Cu and Cd on mitochondrial H2O2 emission depended on the substrate while those for Zn were similar during glutamate-malate and succinate oxidation. Cu + Zn and Cu + Cd mixtures exhibited antagonistic interactions wherein Cu reduced the effects of both Cd and Zn, suggesting that Cu can mitigate oxidative distress caused by Cd or Zn. Binary combinations of the metals acted additively to reduce the rate constant and increase the half-life of H2O2 consumption while concomitantly suppressing thioredoxin reductase and stimulating glutathione peroxidase activities. Collectively, our study indicates that binary mixtures of Cu, Zn, and Cd act additively or antagonistically to modulate H2O2 homeodynamics in heart mitochondria.