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Materials (Basel, Switzerland) Dec 2023As a kind of emerging contaminant, organoarsenic compounds have drawn wide concern because of their considerable solubilities in water, and the highly toxic inorganic...
As a kind of emerging contaminant, organoarsenic compounds have drawn wide concern because of their considerable solubilities in water, and the highly toxic inorganic arsenic species formed during their biotic and abiotic degradation in the natural environment. Thus, the effective removal and studying of the adsorption mechanism of organoarsenic compounds are of significant urgency. In this work, MnFeO and MnFeO/graphene were prepared through a facile solvothermal method. From the results of the Transmission Electron Microscope (TEM) characterization, it can be found that MnFeO nanoparticles were uniformly distributed on the surface of the graphene. And the specific surface area of the MnFeO/graphene was about 146.39 m g, much higher than that of the MnFeO (86.15 m g). The interactions between organoarsenic compounds and adsorbents were conducted to study their adsorption behavior and mechanism. The maximum adsorption capacities of MnFeO/graphene towards p-arsanilic acid (p-ASA) and roxarsone (ROX) were calculated to be 22.75 and 30.59 mg g. Additionally, the ionic strength, negative ions, and humus were introduced to investigate the adsorption performance of organoarsenic compounds. Electrostatic adsorption and surface complexation are the primary adsorption mechanisms on account of X-ray photoelectron spectroscopy (XPS) and the Fourier-transform infrared spectroscopy (FT-IR) analysis. This research extends the knowledge into studying the interaction between organoarsenic species and hybrid nanomaterials in the natural environment.
PubMed: 38138778
DOI: 10.3390/ma16247636 -
Frontiers in Neurology 2023Betahistine is widely used for the treatment of various vestibular disorders. However, the approved oral administration route and maximum daily dose are evidently not...
INTRODUCTION
Betahistine is widely used for the treatment of various vestibular disorders. However, the approved oral administration route and maximum daily dose are evidently not effective in clinical trials, possibly due to a major first-pass metabolism by monoamine oxidases (MAOs). The current study aimed to test different application routes (i.v./s.c./p.o.), doses, and concurrent medication (with the MAO-B inhibitor selegiline) for their effects on behavioral recovery and cerebral target engagement following unilateral labyrinthectomy (UL) in rats.
METHODS
Sixty rats were subjected to UL by transtympanic injection of bupivacaine/arsanilic acid and assigned to five treatment groups: i.v. low-dose betahistine (1 mg/kg bid), i.v. high-dose betahistine (10 mg/kg bid), p.o. betahistine (1 mg/kg bid)/selegiline (1 mg/kg once daily), s.c. betahistine (continuous release of 4.8 mg/day), and i.v. normal saline bid (sham treatment; days 1-3 post-UL), respectively. Behavioral testing of postural asymmetry, nystagmus, and mobility in an open field was performed seven times until day 30 post-UL and paralleled by sequential cerebral [F]-FDG-μPET measurements.
RESULTS
The therapeutic effects of betahistine after UL differed in extent and time course and were dependent on the dose, application route, and selegiline co-medication: Postural asymmetry was significantly reduced on 2-3 days post-UL by i.v. high-dose and s.c. betahistine only. No changes were observed in the intensity of nystagmus across groups. When compared to sham treatment, movement distance in the open field increased up to 5-fold from 2 to 30 days post-UL in the s.c., i.v. high-dose, and p.o. betahistine/selegiline groups. [F]-FDG-μPET showed a dose-dependent rCGM increase in the ipsilesional vestibular nucleus until day 3 post-UL for i.v. high- vs. low-dose betahistine and sham treatment, as well as for p.o. betahistine/selegiline and s.c. betahistine vs. sham treatment. From 1 to 30 days post-UL, rCGM increased in the thalamus bilaterally for i.v. high-dose betahistine, s.c. betahistine, and p.o. betahistine/selegiline vs. saline treatment.
DISCUSSION
Betahistine has the potential to augment the recovery of dynamic deficits after UL if the administration protocol is optimized toward higher effective plasma levels. This may be achieved by higher doses, inhibition of MAO-based metabolism, or a parenteral route. imaging suggests a drug-target engagement in central vestibular networks.
PubMed: 37538257
DOI: 10.3389/fneur.2023.1175481 -
Biomedicines Aug 2022Damage to the peripheral vestibular system is known to generate a syndrome characterized by postural, locomotor, oculomotor, perceptual and cognitive deficits. Current...
Damage to the peripheral vestibular system is known to generate a syndrome characterized by postural, locomotor, oculomotor, perceptual and cognitive deficits. Current pharmacological therapeutic solutions for these pathologies lack specificity and efficacy. Recently, we demonstrated that apamin, a specific SK channel blocker, significantly reduced posturo-locomotor and oculomotor deficits in the cat and the rat. The aim of the present study was to test the antivertigo potential of compounds belonging to the SK antagonists family, such as Acacetin and Fluoxetine. Young rats were subjected to unilateral ototoxic lesions of the vestibular organ using transtympanic administration of arsanilic acid (TTA) to evoke unilateral vestibular loss (UVL). Vestibular syndrome was monitored using behavioural evaluation allowing appreciation of the evolution of static and dynamic posturo-locomotor deficits. A significant effect of the TTA insult was only found on the distance moved, the mean body velocity and the not moving time. From day 2 to week 2 after TTA, the distance moved and the mean body velocity were significantly decreased, while the not moving time was significantly increased. Acacetin does not evoke any significant change in the vestibular posturo-locomotor parameters' kinetics. Administration of Fluoxetine two weeks before TTA and over three weeks after TTA (preventive group) does not evoke any significant change in the vestibular posturo-locomotor parameters' kinetics. Administration of Fluoxetine from three weeks after TTA significantly delayed the functional recovery. This study demonstrates that Acacetin or Fluoxetine in TTA vestibulo-injured rats does not bring any significant benefit on the posture and locomotor balance deficits.
PubMed: 36140199
DOI: 10.3390/biomedicines10092097 -
Molecules (Basel, Switzerland) Dec 2021A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation...
A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation of nanomaterials, polyethyleneimine (PEI) improved the stability of the solution and acted as a reducing agent to generate reduced graphene oxide (rGO) with relatively strong conductivity, thereby promoting the transfer of electrons. The dual conductivity of rGO and silver nanoparticles (AgNPs) improved the sensitivity of the sensor. The synthesis of nanomaterials were confirmed by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. In the optimal experiment conditions, the sensor could achieve the detection range of 0.50-500 ng mL and the limit of detection (LOD) of 0.38 ng mL (S/N = 3). Moreover, the sensor exhibited excellent specificity and acceptable stability, suggesting that the proposed sensor possessed a good potential in ASA detection. Thus, the as-prepared biosensor may be a potential way for detecting other antibiotics in meat and animal-derived foods.
Topics: Arsanilic Acid; Biosensing Techniques; Electrochemical Techniques; Graphite; Immunoassay; Limit of Detection; Metal Nanoparticles; Nanocomposites; Polyethyleneimine; Reproducibility of Results; Silver
PubMed: 35011402
DOI: 10.3390/molecules27010172 -
NeuroImage Feb 2021Unilateral damage to the inner ear results in an acute vestibular syndrome, which is compensated within days to weeks due to adaptive cerebral plasticity. This process,...
Unilateral damage to the inner ear results in an acute vestibular syndrome, which is compensated within days to weeks due to adaptive cerebral plasticity. This process, called central vestibular compensation (VC), involves a wide range of functional and structural mechanisms at the cellular and network level. The short-term dynamics of whole-brain functional network recruitment and recalibration during VC has not been depicted in vivo. The purpose of this study was to investigate the interplay of separate and distinct brain regions and in vivo networks in the course of VC by sequential [F]-FDG-PET-based statistical and graph theoretical analysis with the aim of revealing the metabolic connectome before and 1, 3, 7, and 15 days post unilateral labyrinthectomy (UL) in the rat. Temporal changes in metabolic brain connectivity were determined by Pearson's correlation (|r| > 0.5, p < 0.001) of regional cerebral glucose metabolism (rCGM) in 57 segmented brain regions. Metabolic connectivity analysis was compared to univariate voxel-wise statistical analysis of rCGM over time and to behavioral scores of static and dynamic sensorimotor recovery. Univariate statistical analysis revealed an ipsilesional relative rCGM decrease (compared to baseline) and a contralesional rCGM increase in vestibular and limbic networks and an increase in bilateral cerebellar and sensorimotor networks. Quantitative analysis of the metabolic connections showed a maximal increase from baseline to day 3 post UL (interhemispheric: 2-fold, ipsilesional: 3-fold, contralesional: 12-fold) and a gradual decline until day 15 post UL, which paralleled the dynamics of vestibular symptoms. In graph theoretical analysis, an increase in connectivity occurred especially within brain regions associated with brainstem-cerebellar and thalamocortical vestibular networks and cortical sensorimotor networks. At the symptom peak (day 3 post UL), brain networks were found to be organized in large ensembles of distinct and highly connected hubs of brain regions, which separated again with progressing VC. Thus, we found rapid changes in network organization at the subcortical and cortical level and in both hemispheres, which may indicate an initial functional substitution of vestibular loss and subsequent recalibration and reorganization of sensorimotor networks during VC.
Topics: Adaptation, Physiological; Animals; Arsanilic Acid; Brain; Connectome; Fluorodeoxyglucose F18; Glucose; Locomotion; Neural Pathways; Neuronal Plasticity; Nystagmus, Pathologic; Positron-Emission Tomography; Postural Balance; Radiopharmaceuticals; Rats; Vestibular Diseases; Vestibule, Labyrinth
PubMed: 33249212
DOI: 10.1016/j.neuroimage.2020.117588 -
Brain Sciences Nov 2019When vestibular function is lost, vestibular compensation works for the reacquisition of body balance. For the study of vestibular dysfunction and vestibular...
When vestibular function is lost, vestibular compensation works for the reacquisition of body balance. For the study of vestibular dysfunction and vestibular compensation, surgical or chemical labyrinthectomy has been performed in various animal species. In the present study, we performed chemical labyrinthectomy using arsanilic acid in mice and investigated the time course of vestibular compensation through behavioral observations and histological studies. The surgical procedures required only paracentesis and storage of 50 µL of -arsanilic acid sodium salt solution in the tympanic cavity for 5 min. From behavioral observations, vestibular functions were worst at 2 days and recovered by 7 days after surgery. Spontaneous nystagmus appeared at 1 day after surgery with arsanilic acid and disappeared by 2 days. Histological studies revealed specific damage to the vestibular endorgans. In the ipsilateral spinal vestibular nucleus, the medial vestibular nucleus, and the contralateral prepositus hypoglossal nucleus, a substantial number of c-Fos-immunoreactive cells appeared by 1 day after surgery with arsanilic acid, with a maximum increase in number by 2 days and complete disappearance by 7 days. Taken together, these findings indicate that chemical labyrinthectomy with arsanilic acid and the subsequent observation of vestibular compensation is a useful strategy for elucidation of the molecular mechanisms underlying vestibular pathophysiologies.
PubMed: 31752103
DOI: 10.3390/brainsci9110329 -
Applied and Environmental Microbiology Jan 2020The organoarsenical feed additive 4-hydroxy-3-nitrobenzenearsonic acid (roxarsone [ROX]) is widely used and released into the environment. We previously showed a...
-Hydroxyarylamine -Acetyltransferases Catalyze Acetylation of 3-Amino-4-Hydroxyphenylarsonic Acid in the 4-Hydroxy-3-Nitrobenzenearsonic Acid Transformation Pathway of sp. Strain CZ-1.
The organoarsenical feed additive 4-hydroxy-3-nitrobenzenearsonic acid (roxarsone [ROX]) is widely used and released into the environment. We previously showed a two-step pathway of ROX transformation by sp. strain CZ-1 involving the reduction of ROX to 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA) and the acetylation of 3-AHPAA to -acetyl-4-hydroxy--arsanilic acid (N-AHPAA) (K. Huang, H. Peng, F. Gao, Q. Liu, et al., Environ Pollut 247:482-487, 2019, https://doi.org/10.1016/j.envpol.2019.01.076). In this study, we identified two genes ( and ), encoding -hydroxyarylamine -acetyltransferases, as responsible for 3-AHPAA acetylation in sp. strain CZ-1. The results of genetic disruption and complementation showed that both genes are involved in ROX biotransformation and that is the major 3-AHPAA acetyltransferase gene. Quantitative reverse transcription-PCR analysis showed that the relative expression level of was 3-fold higher than that of Each of the recombinant NhoAs was overexpressed in BL21 and homogenously purified as a dimer by affinity chromatography. Both purified NhoAs catalyzed acetyl coenzyme A-dependent 3-AHPAA acetylation. The values of 3-AHPAA for NhoA1 and NhoA2 were 151.5 and 428.3 μM, respectively. Site-directed mutagenesis experiments indicated that two conserved arginine and cysteine residues of each NhoA were necessary for their enzyme activities. Roxarsone (ROX) is an organoarsenic feed additive that has been widely used in poultry industries for growth promotion, coccidiosis control, and meat pigmentation improvement for more than 70 years. Most ROX is excreted in the litter and dispersed into the environment, where it is transformed by microbes into different arsenic-containing compounds. A major product of ROX transformation is -acetyl-4-hydroxy--arsanilic acid (N-AHPAA), which is also used as a clinical drug for treating refractory bacterial vaginosis. Here, we report the cloning and functional characterization of two genes encoding -hydroxyarylamine -acetyltransferases, NhoA1 and NhoA2, in sp. strain CZ-1, which catalyze the acetylation of 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA) formed by the reduction of ROX to N-AHPAA. This study provides new insights into the function of -hydroxyarylamine -acetyltransferase in the transformation of an important organoarsenic compound.
Topics: Acetylation; Acetyltransferases; Arsenicals; Bacterial Proteins; Enterobacter; Metabolic Networks and Pathways
PubMed: 31676473
DOI: 10.1128/AEM.02050-19 -
Environment International Jun 2019p-Arsanilic acid (p-ASA) and roxarsone (ROX) are two major phenylarsenic feed additives that are still widely used in many countries, and the land application of animal...
A simple treatment method for phenylarsenic compounds: Oxidation by ferrate (VI) and simultaneous removal of the arsenate released with in situ formed Fe(III) oxide-hydroxide.
p-Arsanilic acid (p-ASA) and roxarsone (ROX) are two major phenylarsenic feed additives that are still widely used in many countries, and the land application of animal waste containing these compounds could introduce large quantities of arsenic into the environment. In this study, we proposed a treatment scheme for animal waste that involves leaching of p-ASA/ROX out of the manure first by water, then oxidation by ferrate (Fe(VI)) and removal of the arsenate released by in situ formed Fe(III) oxide-hydroxide. The effects of solution pH, dosage of Fe(VI), solution ionic strength, and matrix species on the treatment performance were systematically evaluated. Initial solution pH values of 4.1 and 2.0 were chosen for the oxidation of p-ASA and ROX, respectively, while efficient arsenate removal could be achieved with relatively small adjustment of the final solution pH (to 4.0). The pH-dependent second-order rate constants for the reactions between ferrate and p-ASA and ROX over the pH range of 2.0-12.0 were estimated to be 7.13 × 10-2.01 × 10 and 8.91 × 10-1.65 × 10 M s, respectively. The degradation pathways of p-ASA/ROX during ferrate oxidation were proposed based on the inorganic and organic intermediates identified. Depending on the levels of p-ASA/ROX, effective treatment could be achieved through flexible adjustment of the Fe(VI) dosage. p-ASA/ROX (10 mg-As/L) in swine manure leachate could be efficiently treated by ferrate oxidation within 5 min, with the overall arsenic removal efficiency higher than 99.2%. The treatment performance was barely affected by the presence of common ions (K, Ca, Na, Mg, SO, NO, and Cl), while humic acid, Mn, Ni, Fe, and Co inhibited p-ASA/ROX oxidation. The presence of PO and NH could accelerate the oxidation of p-ASA/ROX, but PO and humic acid compromised sorptive removal of the released arsenate due to their competitive sorption on the Fe(III) oxide-hydroxide precipitate. Ferrate oxidation is green and fast, and the operation is simple, thus it could serve as a promising and environment-friendly option for mitigating the risk of phenylarsenic feed additives in animal waste.
Topics: Animals; Arsenates; Ferric Compounds; Hydrogen-Ion Concentration; Hydroxides; Iron; Oxidation-Reduction; Oxides; Swine
PubMed: 31003056
DOI: 10.1016/j.envint.2019.03.059 -
Journal of Neuroscience Methods Feb 2018The vestibular lesion (VL) is required to examine the physiological function of the vestibular system in animals. Toxic chemicals or electrical apparatus have been used... (Comparative Study)
Comparative Study
BACKGROUND
The vestibular lesion (VL) is required to examine the physiological function of the vestibular system in animals. Toxic chemicals or electrical apparatus have been used for the VL, however, they are not ideal as they have low specificity, and can result in unintended damage, and systemic toxic effect.
NEW METHOD
Localized vibration-induced VL, using an ultrasonicator, is expected to overcome the problems associated with chemical and electrical lesions. Thus, we examined the effect of the ultrasonication on the VL from the aspects of both the physiological function and histology in the present study.
RESULTS
and Comparison with Existing Method(s) Complete VL, which was evaluated by deterioration of swimming skills, righting reflex, and body stability, was induced using an ultrasonicator or electrical apparatus. Histological evaluation shows that hair cell layers in the saccule and utricle were completely destroyed in both methods Furthermore, significant drop in body mass was observed in VL. However, abscess at the cranial base was observed in VL induced by the electrical apparatus in ICR mice. Complete chemically-induced VL was observed in C57BL/6J but not ICR mice, and systemic leakage of the toxic chemicals (arsenic) was not detectable even 1day after surgery.
CONCLUSIONS
Compared to the electrical apparatus, the ultrasonicator is useful for inducing VL in ICR and C57BL/6J mice, as it results in less non-specific damage. Toxic chemicals can be used for inducing VL in C57BL/6J mice; however, this method does not ensure complete disruption of the hair cells in the saccule and utricle.
Topics: Animals; Arsanilic Acid; Body Size; Disease Models, Animal; Male; Mice, Inbred C57BL; Mice, Inbred ICR; Physical Stimulation; Species Specificity; Ultrasonics; Vestibular Diseases; Vestibular Function Tests; Vestibule, Labyrinth; Vibration
PubMed: 29198950
DOI: 10.1016/j.jneumeth.2017.11.021 -
Acta Crystallographica. Section E,... Feb 2017The structures of the alkali metal (K, Rb and Cs) complex salts with 4-amino-phenyl-arsonic acid (-arsanilic acid) manifest an isotypic series with the general formula...
The structures of the alkali metal (K, Rb and Cs) complex salts with 4-amino-phenyl-arsonic acid (-arsanilic acid) manifest an isotypic series with the general formula [(CHAsNO)(HO)], with = K {poly[di-μ-4-amino-phenyl-arsonato-tri-μ-aqua-dipotassium], [K(CHAsNO)(HO)], (I)}, Rb {poly[di-μ-4-amino-phenyl-arsonato-tri-μ-aqua-dirubidium], [Rb(CHAsNO)(HO)], (II)}, and Cs {poly[di-μ-4-amino-phenyl-arsonato-tri-μ-aqua-dirubidium], [Cs(CHAsNO)(HO)], (III)}, in which the repeating structural units lie across crystallographic mirror planes containing two independent and different metal cations and a bridging water mol-ecule, with the two hydrogen -arsanilate ligands and the second water mol-ecule lying outside the mirror plane. The bonding about the two metal cations in all complexes is similar, one five-coordinate, the other progressing from five-coordinate in (I) to eight-coordinate in both (II) and (III), with overall -O bond-length ranges of 2.694 (5)-3.009 (7) (K), 2.818 (4)-3.246 (4) (Rb) and 2.961 (9)-3.400 (10) Å (Cs). The additional three bonds in (II) and (III) are the result of inter-metal bridging through the water ligands. Two-dimensional coordination polymeric structures with the layers lying parallel to (100) are generated through a number of bridging bonds involving the water mol-ecules (including hydrogen-bonding inter-actions), as well as through the arsanilate O atoms. These layers are linked across [100] through amine N-H⋯O hydrogen bonds to arsonate and water O-atom acceptors, giving overall three-dimensional network structures.
PubMed: 28217343
DOI: 10.1107/S2056989017000445