Identification of genes associated with the silk gland size using multi-omics in silkworm (Bombyx mori).

Silk gland size in silkworms (Bombyx mori) affects silk output. However, the molecular mechanisms by which genes regulate silk gland size remain unclear. In this study, silk glands from three pure silkworm strains (A798, A306 and XH) with different silk gland weight phenotypes were compared using transcriptomics and proteomics to identify differentially expressed genes (DEGs) and proteins (DEPs). When comparing A798 to A306 and A798 to XH, 830 and 469 DEGs were up-regulated, respectively. These genes were related to the gene ontology terms, metabolic process, transport activity and biosynthesis process. In addition, 372 and 302 up-regulated differentially expressed proteins were detected in A798 to A306 and A798 to XH, respectively, related to the gene ontology terms, ribosome and protein export, ribosome and polypeptide biosynthesis processes. Moreover, combined transcriptomics, proteomics and weighted correlation network analyses showed that five genes (BGIBMGA002524, BGIBMGA002629, BGIBMGA005659, BGIBMGA005711 and BGIBMGA010889) were significantly associated with the silk gland weight. Reverse Transcription-quantitative real-time Polymerase Chain Reaction (RT-qPCR) and Enzyme linked immunosorbent assay (ELISA) were used to verify the mRNA and protein expression of five genes in the silk glands and tissues of 18 silkworm strains. The results showed that four genes have higher expression levels in heavier silk glands. These genes are associated with glycogen metabolism, fatty acid synthesis and branched chain amino acid metabolism, thus potentially promoting growth and silk protein synthesis. These findings provide valuable insights into the molecular mechanisms underlying the relationship between silk gland weight and silk yield in silkworms.

Anti-inflammatory and anti-oxidative electrospun nanofiber membrane promotes diabetic wound healing via macrophage modulation.

BACKGROUND: In the inflammatory milieu of diabetic chronic wounds, macrophages undergo substantial metabolic reprogramming and play a pivotal role in orchestrating immune responses. Itaconic acid, primarily synthesized by inflammatory macrophages as a byproduct in the tricarboxylic acid cycle, has recently gained increasing attention as an immunomodulator. This study aims to assess the immunomodulatory capacity of an itaconic acid derivative, 4-Octyl itaconate (OI), which was covalently conjugated to electrospun nanofibers and investigated through in vitro studies and a full-thickness wound model of diabetic mice. RESULTS: OI was feasibly conjugated onto chitosan (CS), which was then grafted to electrospun polycaprolactone/gelatin (PG) nanofibers to obtain P/G-CS-OI membranes. The P/G-CS-OI membrane exhibited good mechanical strength, compliance, and biocompatibility. In addition, the sustained OI release endowed the nanofiber membrane with great antioxidative and anti-inflammatory activities as revealed in in vitro and in vivo studies. Specifically, the P/G-CS-OI membrane activated nuclear factor-erythroid-2-related factor 2 (NRF2) by alkylating Kelch-like ECH-associated protein 1 (KEAP1). This antioxidative response modulates macrophage polarization, leading to mitigated inflammatory responses, enhanced angiogenesis, and recovered re-epithelization, finally contributing to improved healing of mouse diabetic wounds. CONCLUSIONS: The P/G-CS-OI nanofiber membrane shows good capacity in macrophage modulation and might be promising for diabetic chronic wound treatment.

Metabolomics captures the differential metabolites in the replication pathway of snakehead vesiculovirus regulated by glutamine.

Snakehead vesiculovirus (SHVV) is a negative-sense single-stranded RNA virus that infects snakehead fish. This virus leads to illness and mortality, causing significant economic losses in the snakehead aquaculture industry. The replication and spread of SHVV in cells, which requires glutamine as a nitrogen source, is accompanied by alterations in intracellular metabolites. However, the metabolic mechanisms underlying the inhibition of viral replication by glutamine deficiency are poorly understood. This study utilized liquid chromatography-mass spectrometry to measure the differential metabolites between the channel catfish Parasilurus asotus ovary cell line infected with SHVV under glutamine-containing and glutamine-deprived conditions. Results showed that the absence of glutamine regulated 4 distinct metabolic pathways and influenced 9 differential metabolites. The differential metabolites PS(16:0/16:0), 5,10-methylene-THF, and PS(18:0/18:1(9Z)) were involved in amino acid metabolism. In the nuclear metabolism functional pathway, differential metabolites of guanosine were observed. In the carbohydrate metabolism pathway, differential metabolites of UDP-d-galacturonate were detected. In the signal transduction pathway, differential metabolites of SM(d18:1/20:0), SM(d18:1/22:1(13Z)), SM(d18:1/24:1(15 Z)), and sphinganine were found. Among them, PS(18:0/18:1(9Z)), PS(16:0/16:0), and UDP-d-galacturonate were involved in the synthesis of phosphatidylserine and glycoprotein. The compound 5,10-methylene-THF provided raw materials for virus replication, and guanosine and sphingosine are related to virus virulence. The differential metabolites may collectively participate in the replication, packaging, and proliferation of SHVV under glutamine deficiency. This study provides new insights and potential metabolic targets for combating SHVV infection in aquaculture through metabolomics approaches.

Comparison of exsanguination and hemostasis devices for Limb surgery: a multicenter randomized controlled study.

BACKGROUND: Excessive intraoperative bleeding remains a challenge in limb surgeries. The exsanguination tourniquet ring has emerged as a potential solution for effective exsanguination and hemostasis. This study aims to evaluate its efficacy and safety compared to the conventional exsanguination and hemostasis approach (pneumatic tourniquet combined with Esmarch bandage). METHODS: This randomized controlled trial evaluates the exsanguination tourniquet ring's effectiveness and safety versus the conventional approach in 220 participants undergoing various limb surgeries. Allocation included experimental and control groups, assesses through efficacy (including intraoperative and total blood loss, hemoglobin levels, and exsanguination and hemostasis effectiveness) and safety (adverse event occurrence) indicators. RESULTS: The experimental group (n = 110) utilizes the exsanguination tourniquet ring, while the control group (n = 110) employs the conventional approach. As for intraoperative blood loss, the experimental group is non-inferior to the control group (p-value < 0.001). While no significant difference is found in total blood loss (for the full analysis set, p-value = 0.442; for the per protocol set, p-value = 0.976) and differences in postoperative and preoperative hemoglobin levels (for the full analysis set, p-value = 0.502; for the per protocol set, p-value = 0.928). Regarding exsanguination and hemostasis effectiveness, the full analysis set reveals significantly superior ratings in the experimental group compared to the control group (p-value = 0.002 < 0.05), while the per protocol set analysis indicates no significant difference between the groups (p-value = 0.504). As for safety indicators, adverse events related to the device are minimal in two groups, with only one severe event unrelated to the device. CONCLUSIONS: The exsanguination tourniquet ring is an effective and safe device for intraoperative blood loss control in various limb surgeries. TRIAL REGISTRATION: Comparison of Exsanguination and Hemostasis Devices for Limb Surgery A Prospective Multicenter Randomized Controlled Study, ChiCTR2300077998, 11/27/2023.

The Effect of Distance Education on Self-care in Patients With Heart Failure in the Chronic or Stable Phase: A Systematic Review and Meta-analysis.

BACKGROUND: Health education is important for self-care in patients with heart failure. However, the evidence for the effect of distance education as an intervention to deliver instruction for patients after discharge through digital devices on self-care is limited. OBJECTIVES: In this study, our aim was to explore the effect of distance education on self-care in patients with heart failure. METHODS: We searched 11 electronic databases and 3 trial registries for randomized controlled trials with low risk of bias and high-quality evidence to compare the effect of usual and distance education on self-care. Quality appraisal was performed using the Cochrane Risk of Bias Tool. Using the Review Manager 5.4 tool, a meta-analysis was conducted. Certainty of the evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). RESULTS: Fifteen articles were eligible for this study. Compared with usual education, distance education improved self-care maintenance (mean difference [MD], 6.62; 95% confidence interval [CI], 3.93-9.31; GRADE, moderate quality), self-care management (MD, 5.10; 95% CI, 3.25-6.95; GRADE, high quality), self-care confidence (MD, 6.66; 95% CI, 4.82-8.49; GRADE, high quality), heart failure knowledge (MD, 0.78; 95% CI, 0.01-1.56; GRADE, moderate quality), and quality of life (MD, -5.35; 95% CI, -8.73 to -1.97; GRADE, moderate quality). Subgroup analysis revealed distance education was more effective than usual education in self-care when the intervention was conducted for 1 to 6 months, more than 3 times per month, and a single intervention lasting more than 30 minutes. CONCLUSIONS: This review shows the benefits of distance education on self-care, heart failure knowledge, and quality of life of patients with heart failure. The intervention duration, frequency, and duration of a single intervention could have affected the intervention effect.

A Multifunctional Asymmetric Fabric for Sustained Electricity Generation from Multiple Sources and Simultaneous Solar Steam Generation.

Harvesting electrical energy from water and moisture has emerged as a novel ecofriendly energy conversion technology. Herein, a multifunctional asymmetric polyaniline/carbon nanotubes/poly(vinyl alcohol) (APCP) that can produce electric energy from both saline water and moisture and generate fresh water simultaneously is developed. The constructed APCP possesses a negatively charged porous structure that allows continuous generation of protons and ion diffusion through the material, and a hydrophilicity-hydrophobic interface which results in a constant potential difference and sustainable output. A single APCP can maintain stable output for over 130 h and preserve a high voltage of 0.61 V, current of 81 µA, and power density of 82.4 µW cm-3 with 0.15 cm3 unit size in the water-induced electricity generation process. When harvesting moisture energy, the APCP creates dry-wet asymmetries and triggers the spontaneous development of electrical double layer with a current density of 1.25 mA cm-3 , sufficient to power small electronics. A device consisting of four APCP can generate stable electricity of 3.35 V and produce clean water with an evaporation rate of 2.06 kg m-2  h-1 simultaneously. This work provides insights into the fabrication of multifunctional fabrics for multisource energy harvesting and simultaneous solar steam generation.

The diagnostic performance of high-resolution magnetic resonance-vessel wall imaging in differentiating atherosclerosis-associated moyamoya vasculopathy from moyamoya disease.

OBJECTIVES: To evaluate the diagnostic performance of high-resolution magnetic resonance-vessel wall imaging (HRMR-VWI) in differentiating moyamoya disease (MMD) from atherosclerosis-associated moyamoya vasculopathy (AS-MMV) and investigate an accurate approach for the differential diagnosis. METHODS: Adult patients who were diagnosed as MMD or AS-MMV and underwent HRMR-VWI were retrospectively included. The three vessel wall features (outer diameter (OD), remodeling index (RI), and pattern of vessel wall thickening) of middle cerebral artery (MCA) in identifying MMD from AS-MMV were assessed and compared. Furthermore, subgroup analysis stratified by degree of luminal stenosis was performed and the cutoff values of different vessel wall features in differentiating MMD from AS-MMV were also calculated. RESULTS: A total of 265 patients (160 cases of MMD and 105 AS-MMV) were included. Patients with AS-MMV had greater OD and RI and were more likely to exhibit eccentric thickening of vessel wall compared to those with MMD (all p < 0.001). The ROC analysis showed that the AUC value of OD was greater than that of RI (0.912 vs. 0.889, p = 0.007) in differentiating MMD from AS-MMV, and their corresponding cutoff values were 1.77 mm and 0.27, respectively. And the AUC value of pattern of vessel wall thickening was 0.786 in non-occluded patients. With the increase of lumen stenosis, the discrimination power of the three indicators enhanced correspondingly. CONCLUSIONS: HRMR-VWI is valuable in distinguishing MMD from AS-MMV. The OD of MCA has better diagnostic performance in differentiating AS-MMV from MMD compared to RI and pattern of vessel wall thickening. CLINICAL RELEVANCE STATEMENT: The outer diameter of the involved artery proved to be both accurate and convenient in distinguishing atherosclerosis-associated moyamoya vasculopathy from moyamoya disease and may provide a quantitative reference for clinical diagnosis. KEY POINTS: High-resolution magnetic resonance-vessel wall imaging is valuable in distinguishing atherosclerosis-associated moyamoya vasculopathy from moyamoya disease. Compared to remodeling index and pattern of vessel wall thickening, outer diameter is more accurate in differentiating atherosclerosis-associated moyamoya vasculopathy from moyamoya disease. With the increase of lumen stenosis, the discrimination power of outer diameter, remodeling index, and pattern of vessel wall thickening enhanced correspondingly.

Exposure Order to Photoaging and Humic Acids Significantly Modifies the Aggregation and Transformation of Nanoplastics in Aqueous Solutions.

The colloidal stability of nanoplastics in aqueous solutions is greatly regulated by photoaging and dissolved organic matter (DOM). However, how the exposure order to sunlight and DOM modifies the environmental behavior of nanoplastics is seldomly determined. Here, with two different exposure orders, we investigated the impact of molecular-weight (MW)-fractionated humic acids (HAs) derived from biochar and the Suwannee River, respectively, on the aggregation of poly(ethylene terephthalate) nanoplastics (PET-NPs) in mono- and divalent electrolyte solutions. For exposure pattern (i) (photoaging followed by HA coating), photoaged PET-NPs had more oxidized surfaces and exhibited 22-320% higher binding affinity to HAs (especially the higher MW fractions) than the pristine counterparts, which greatly improved the dispersion of PET-NPs. For exposure pattern (ii) (HA coating followed by photoaging), HA-PET assemblies were formed, the dispersion of which increased with increasing irradiation time and was significantly higher than that of the samples in the exposure pattern (i) at the end of the experiment. This high dispersion of photoaged HA-PET assemblies was ascribed to the extra oxidation of PET by reactive oxygen species generated in the PET-HA interfaces during photoaging. These findings highlight the "active nature" of HA-PET assemblies, which provide new insight into the reaction of HA with nanoplastics beyond adsorption in the natural environment.

Transcranial Direct Current Stimulation (tDCS) over the Left Dorsal Lateral Prefrontal Cortex in Children with Autism Spectrum Disorder (ASD).

Recently, transcranial direct current stimulation (tDCS) has been applied to relieve symptoms in individuals with autism spectrum disorder (ASD). In this prospective, parallel, single-blinded, randomized study, we investigate the modulation effect of three-week tDCS treatment at the left dorsal lateral prefrontal cortex (DLPFC) in children with ASD. 47 children with ASD were enrolled, and 40 (20 in each group) completed the study. The primary outcomes are Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), and the Repetitive Behavior Scale-Revised (RBS-R). We found that children with ASD can tolerate three-week tDCS treatment with no serious adverse events detected. A within-group comparison showed that real tDCS, but not sham tDCS, can significantly reduce the scores of CARS, Children's Sleep Habits Questionnaire (CSHQ), and general impressions in CARS (15th item). Real tDCS produced significant score reduction in the CSHQ and in CARS general impressions when compared to the effects of sham tDCS. The pilot study suggests that three-week left DLPFC tDCS is well-tolerated and may hold potential in relieving some symptoms in children with ASD.

Impacts of Proteins on Dissolution and Sulfidation of Silver Nanowires in an Aquatic Environment: Importance of Surface Charges.

With increasing utilization of silver nanomaterials, growing concerns are raised on their deleterious effects to the environment. Once discharged in an aquatic environment, the interactions between silver nanowires (AgNWs) and proteins may significantly affect the environmental behaviors, fate, and toxicities of AgNWs. In the present study, three representative model proteins, including ovalbumin (OVA), bovine serum albumin (BSA), and lysozyme (LYZ), were applied to investigate the impacts of the interactions between proteins and AgNWs on the transformations (oxidative dissolution and sulfidation) of AgNWs in an aquatic environment. Fluorescence spectroscopy and isothermal titration calorimetry analyses indicated that there was very weak interaction between OVA or BSA and AgNWs, but there was a strong interaction between the positively charged LYZ and the negatively charged AgNWs. The presence of LYZ not only reversed the surface charge of AgNWs but also resulted in the breakup of the nanowire structure and increased the reactive surface area. The positively charged surface of AgNWs in the presence of LYZ favored the access of sulfide ions. As a consequence, the kinetics of oxidative dissolution and sulfidation of AgNWs were not affected by OVA and BSA but were significantly facilitated by LYZ. The results shed light on the important roles of electrostatic interactions between AgNWs and proteins, which may have important implications for evaluating the fate and effects of silver nanomaterials in complicated environments.

Probing Mechanisms for the Tissue-Specific Distribution and Biotransformation of Perfluoroalkyl Phosphinic Acids in Common Carp (Cyprinus carpio).

This study investigated the tissue-specific accumulation and biotransformation of 6:6 and 8:8 perfluoroalkyl phosphinic acids (PFPiA) in common carp (Cyprinus carpio) during 90 d exposure and 30 d depuration in water in the laboratory. Both 6:6 and 8:8 PFPiAs could quickly accumulate in the carp, and 6:6 PFPiA displayed higher bioaccumulation potential than 8:8 PFPiA. The highest concentrations of PFPiAs were observed in the blood, while the lowest were found in the muscle. The equilibrium dialysis experiment indicated that both PFPiAs had higher binding affinities with the proteins in the fish serum than in liver, which was supported by the molecular docking analysis. The results also indicated that 6:6 PFPiA had higher binding affinities with the serum and liver proteins than 8:8 PFPiA. These results suggested that the tissue-specific distribution of PFPiAs was highly dependent on the binding affinities with the specific proteins. Both in vivo and in vitro experiments consistently indicated that PFPiAs experienced biotransformation and produced perfluoroalkyl phosphonic acids (PFPAs), and biotransformation of 8:8 PFPiA was more active than 6:6 PFPiA. It was worth noting that perfluorohexanonate and perfluorooctanoic acids were identified in fish as metabolites after long-term exposure to PFPiAs for the first time.

Evaluation of PLGA microspheres with triple regimen on long-term survival of vascularized composite allograft - an experimental study.

Systemic immunosuppression is indispensable for vascularized composite allotransplantation (VCA). Daily administration of standard triple therapy regimen of tacrolimus (FK506), mycophenolate mofetil (MMF), and steroid has severe side effects and reduces the compliance of VCA recipients. To overcome these hurdles, FK506/MMF/prednisolone (PDNN) was loaded into PLGA microspheres (PGLA MS). A single injection of FK506/MMF/PDNN-PLGA MS significantly prolonged the survival time of allograft in a rat hind limb transplantation model with a median survival time (MST) of more than 150 days compared to 34.5 days in the group treated orally with FK506/MMF/PDNN and 11 days in the nontreatment allograft and MS control groups. Analysis of showed that FK506/MMF/PDNN-PLGA MS could maintain relatively higher plasma and tissue drug concentrations for a long time. Moreover, histopathology and flow cytometry of circulating mononuclear cells revealed significantly prolonged immunosuppression by the FK506/MMF/PDNN-PLGA MS compared with the orally given FK506/MMF/PDNN. In conclusion, a single injection of FK506/MMF/PDNN-PLGA MS may provide a new approach for long-term prevention of immune rejection in VCA.

Physiologically based pharmacokinetic-pharmacodynamic modeling for prediction of vonoprazan pharmacokinetics and its inhibition on gastric acid secretion following intravenous/oral administration to rats, dogs and humans.

Vonoprazan is characterized as having a long-lasting antisecretory effect on gastric acid. In this study we developed a physiologically based pharmacokinetic (PBPK)-pharmacodynamic (PD) model linking to stomach to simultaneously predict vonoprazan pharmacokinetics and its antisecretory effects following administration to rats, dogs, and humans based on in vitro parameters. The vonoprazan disposition in the stomach was illustrated using a limited-membrane model. In vitro metabolic and transport parameters were derived from hepatic microsomes and Caco-2 cells, respectively. We found the most predicted plasma concentrations and pharmacokinetic parameters of vonoprazan in rats, dogs and humans were within twofold errors of the observed data. Free vonoprazan concentrations (fu × C2) in the stomach were simulated and linked to the antisecretory effects of the drug (I) (increases in pH or acid output) using the fomula dI/dt = k × fu × C2 × (Imax - I) - kd × I. The vonoprazan dissociation rate constant kd (0.00246 min-1) and inhibition index KI (35 nM) for H+/K+-ATPase were obtained from literatures. The vonoprazan-H+/K+-ATPase binding rate constant k was 0.07028 min-1· µM-1 using ratio of kd to KI. The predicted antisecretory effects were consistent with the observations following intravenous administration to rats (0.7 and 1.0 mg/kg), oral administration to dogs (0.3 and 1.0 mg/kg) and oral single dose or multidose to humans (20, 30, and 40 mg). Simulations showed that vonoprazan concentrations in stomach were 1000-fold higher than those in the plasma at 24 h following administration to human. Vonoprazan pharmacokinetics and its antisecretory effects may be predicted from in vitro data using the PBPK-PD model of the stomach. These findings may highlight 24-h antisecretory effects of vonoprazan in humans following single-dose or the sustained inhibition throughout each 24-h dosing interval during multidose administration.

Bioaccumulation kinetics and tissue distribution of silver nanoparticles in zebrafish: The mechanisms and influence of natural organic matter.

The wide application of silver nanoparticles (AgNPs) has inevitably led to their release into the natural aquatic environment. Natural organic matter (NOM) is ubiquitous and would influence the fate and effects of these nanoparticles in such aquatic environments. Here we demonstrate that NOM plays an important role in the bioaccumulation kinetics and tissue distribution of AgNPs in zebrafish. In the presence of humic acid and fulvic acid, the uptake rates of AgNPs decreased while the depuration rates of AgNPs increased. As a result, the bioconcentration factor (BCF) of AgNPs in the entire body of the zebrafish was reduced. AgNPs were mainly taken up by the zebrafish via oral ingestion and were greatly accumulated in the liver, intestine and gill. In the intestine, NOM effectively inhibited the AgNPs from penetrating the cell membranes into internal tissues and also suppressed the disintegration and dissolution of AgNPs in gastrointestinal fluid, thereby decreasing the absorption of Ag by zebrafish. This research underlines the significance of incorporating the effects of NOM into predictive models for accurately assessing the toxicity and ecological risks of nanoparticles in natural aquatic environments.

Uptake Kinetics, Accumulation, and Long-Distance Transport of Organophosphate Esters in Plants: Impacts of Chemical and Plant Properties.

The uptake, accumulation, and long-distance transport of organophosphate esters (OPEs) in four kinds of plants were investigated by hydroponic experiments. The uptake kinetics ( k1,root) of OPEs in plant roots were determined by the binding of OPEs with the proteins in plant roots and apoplastic sap for the hydrophobic compounds, which correlated well with the transpiration capacity of the plants for the hydrophilic compounds. However, the accumulation capacity of OPEs in plant root was controlled by the partition of OPEs to plant lipids. As a consequence, OPEs were taken up the fastest in wheat root as a result of its highest protein content but least accumulated as a result of its lowest lipid content. The translocation factor of the OPEs decreased quickly with the hydrophobicity (log Kow) increasing, suggesting that the hydrophobic OPEs were hard to translocate from roots to shoots. The hydrophilic OPEs, such as tris(2-chloroisopropyl) phosphate and tris(2-butoxyethyl) phosphate, were ambimobile in the plant xylem and phloem, suggesting that they could move to the edible parts of plants and enhanced risk to human health.

Impacts of sulfidation of silver nanowires on the degradation of bisphenol A in water.

Silver nanowires (AgNWs) are widely produced in many electronic and optical products, and could be inevitably discharged into the aquatic environments. Sulfidation is one of the most important transformation processes of AgNWs, and could significantly affect their fate and interactions with other pollutants in aquatic environment. In the present study, the sulfidation products of AgNWs with different atomic ratio of Ag and S were prepared under environmentally relevant conditions. The crystal structure, elemental composition, morphology and size of the sulfidation products were comprehensively characterized by powder X-ray diffraction, UV-vis spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscope. The products were heterostructured nanowires and the Ag2S/Ag molar ratio increased with extension of the reaction time. The produced Ag2S-Ag nanowires displayed a good photocatalytic activity and facilitated the degradation of the copresent organic pollutant bisphenol A (BPA) under simulated sunlight irradiation. As sulfidation time increased, more Ag2S was generated and the Ag2S-Ag composites displayed high promotion effect on BPA degradation. This effect could be ascribed to the favorable synergistic effects between Ag2S and AgNWs, such as high electron-hole separation efficiency and low charge transfer resistance. The chemical scavenger experiments demonstrated that superoxide anion radicals and photogenerated holes in the sulfidation products of AgNWs could be the main reactive species for photocatalytic degradation.

Concentration Dependent Effects of Bovine Serum Albumin on Graphene Oxide Colloidal Stability in Aquatic Environment.

The impacts of a model globular protein (bovine serum albumin, BSA) on aggregation kinetics of graphene oxide (GO) in aquatic environment were investigated through time-resolved dynamic light scattering at pH 5.5. Aggregation kinetics of GO without BSA as a function of electrolyte concentrations (NaCl, MgCl2, and CaCl2) followed the traditional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and the critical coagulation concentration (CCC) was 190, 5.41, and 1.61 mM, respectively. As BSA was present, it affected the GO stability in a concentration dependent manner. At fixed electrolyte concentrations below the CCC values, for example 120 mM NaCl, the attachment efficiency of GO increased from 0.08 to 1, then decreased gradually and finally reached up to zero as BSA concentration increased from 0 to 66.5 mg C/L. The low-concentration BSA depressed GO stability mainly due to electrostatic binding between the positively charged lysine groups of BSA and negatively charged groups of GO, as well as double layer compression effect. With the increase of BSA concentration, more and more BSA molecules were adsorbed on GO, leading to strong steric repulsion which finally predominated and stabilized the GO. These results provided significant information about the concentration dependent effects of natural organic matters on GO stability under environmentally relevant conditions.

Changes in intraepidermal nerve fiber and Langerhans cell densities in the plantar skin of rats after mercuric chloride exposure.

Mercury and its compounds possess strong neurotoxicity and patients with mercury poisoning often report pain and numbness in the distal extremities that conform to the "stocking-glove" pattern. However, no study has investigated whether damage to small nerve fibers is associated with mercury poisoning. The aims of the present study were to evaluate the effects of different doses of mercury chloride (HgCl2 ) on intraepidermal nerve fibers density (IENFD) and Langerhans cells (LCs) in the plantar skin of rats and to assess the possible relationship between changes in IENFD and sensory testing. Male Sprague-Dawley rats were divided into three experimental groups and administered HgCl2 solutions via gavage at three different doses (4.25, 8.5, and 17 mg/kg/day) for 21 days. Subsequently, behavioral tests and pathological changes in IENFD and LCs were assessed at three different time points (1, 2, and 3 weeks). Rats in all three HgCl2 groups exhibited varying degrees of weight and hair loss. Thermal hypersensitivity was evident in all the HgCl2 groups (for middle-2w subgroup, p < 0.05). Mechanical sensitivity tests revealed hyposensitivity in all the HgCl2 groups except the high-1w subgroup. Significant decreases in IENFD (for the high-1w, middle-1w, low-2w, and low-3w subgroups, p < 0.05) and significant increases in the density of LCs (except for the low-1w and high-2w subgroups, all p < 0.05) were found in all groups after HgCl2 exposure. An association analysis revealed a significant correlation between the decrease in IENFD and the increase in LCs densities (r = -0.573, p < 0.01). The present study demonstrated a decrease in IENFD and an increase in LCs density in the plantar skin of rats after HgCl2 poisoning, indicating that damage of the small nerve fibers occurs after mercury poisoning.

Acute liver failure enhances oral plasma exposure of zidovudine in rats by downregulation of hepatic UGT2B7 and intestinal P-gp.

HIV infection is often associated with liver failure, which alters the pharmacokinetics of many drugs. In this study we investigated whether acute liver failure (ALF) altered the pharmacokinetics of the first-line anti-HIV agent zidovudine (AZT), a P-gp/BCRP substrate, in rats. ALF was induced in rats by injecting thioacetamide (TAA, 300 mg·kg-1·d-1, ip) for 2 days. On the second day after the last injection of TAA, the pharmacokinetics of AZT was investigated following both oral (20 mg/kg) and intravenous (10 mg/kg) administration. ALF significantly increased the plasma concentrations of AZT after both oral and intravenous doses of AZT, but without affecting the urinary excretion of AZT. AZT metabolism was studied in rat hepatic microsomes in vitro, which revealed that hepatic UGT2B7 was the main enzyme responsible for the formation of AZT O-glucuronide (GAZT); ALF markedly impaired AZT metabolism in hepatic microsomes, which was associated with the significantly decreased hepatic UGT2B7 expression. Intestinal absorption of AZT was further studied in rats via in situ single-pass intestinal perfusion. Intestinal P-gp function and intestinal integrity were assessed with rhodamine 123 and FD-70, respectively. We found that ALF significantly downregulated intestinal P-gp expression, and had a smaller effect on intestinal BCRP. Further studies showed that ALF significantly increased the intestinal absorption of both rhodamine 123 and AZT without altering intestinal integrity, thus confirming an impairment of intestinal P-gp function. In conclusion, ALF significantly increases the oral plasma exposure of AZT in rats, a result partly attributed to the impaired function and expression of hepatic UGT2B7 and intestinal P-gp.

Acute liver failure impairs function and expression of breast cancer-resistant protein (BCRP) at rat blood-brain barrier partly via ammonia-ROS-ERK1/2 activation.

We once reported that P-glycoprotein (P-GP) and multidrug resistance-associated protein 2 (MRP2) were oppositely regulated at the blood-brain barrier (BBB) of thioacetamide-induced acute liver failure (ALF) rats. This study aimed to investigate whether ALF affected function and expression of breast cancer-resistant protein (BCRP) at the BBB of rats and the role of ammonia in the regulation. ALF rats were developed by intraperitoneal (i.p.) injection of thioacetamide (300 mg/kg) for 2 days. Hyperammonemic rats were developed by NH4 Ac (i.p. 4.5 mmol/kg). BCRP function and expression were measured by brain distribution of specific substrates (prazosin and methotrexate) and western blot, respectively. MDCK-BCRP cells and primarily cultured rat brain microvessel endothelial cells (rBMECs) were employed to investigate possible mechanisms through which ammonia regulated BCRP function and expression. The results showed that both ALF and hyperammonemia significantly weakened function and expression of BCRP in the brain of rats. The function and expression of BCRP in MDCK-BCRP cells and rBMECs were strikingly decreased after exposure to NH4 Cl and H2 O2 , accompanied by remarkable increases in the levels of phosphorylated ERK1/2 and reactive oxygen species (ROS). The altered BCRP expression and function by ammonia and H2 O2 were restored by ROS scavenger N-acetylcysteine and ERK1/2 inhibitor U0126. Markedly increased levels of ERK1/2 phosphorylation and ROS were found in the brains of ALF rats and hyperammonemic rats. All above results indicated ALF down-regulated expression and function of BCRP at BBB of rats partly via hyperammonemia. Activation of ROS-mediated ERK1/2 phosphorylation may be one of the reasons that ammonia impaired BCRP expression and function at the BBB. The present study showed that the expression and function of breast cancer resistant protein (BCRP) at blood-brain barrier (BBB) of thioacetamide-induced ALF rats were down-regulated which partly attribute to hyperammonemia. Activation of ROS-mediated ERK1/2 phosphorylation may be one of the reasons that ammonia suppressed BCRP expression and function. Impaired BCRP at BBB might enhanced pharmacological/toxic effects of corresponding substrates on CNS.