Evaluation of sequence-based predictors for phase-separating protein.

Liquid-liquid phase separation (LLPS) of proteins and nucleic acids underlies the formation of biomolecular condensates in cell. Dysregulation of protein LLPS is closely implicated in a range of intractable diseases. A variety of tools for predicting phase-separating proteins (PSPs) have been developed with the increasing experimental data accumulated and several related databases released. Comparing their performance directly can be challenging due to they were built on different algorithms and datasets. In this study, we evaluate eleven available PSPs predictors using negative testing datasets, including folded proteins, the human proteome, and non-PSPs under near physiological conditions, based on our recently updated LLPSDB v2.0 database. Our results show that the new generation predictors FuzDrop, DeePhase and PSPredictor perform better on folded proteins as a negative test set, while LLPhyScore outperforms other tools on the human proteome. However, none of the predictors could accurately identify experimentally verified non-PSPs. Furthermore, the correlation between predicted scores and experimentally measured saturation concentrations of protein A1-LCD and its mutants suggests that, these predictors could not consistently predict the protein LLPS propensity rationally. Further investigation with more diverse sequences for training, as well as considering features such as refined sequence pattern characterization that comprehensively reflects molecular physiochemical interactions, may improve the performance of PSPs prediction.

Phase III clinical trial comparing the efficacy and safety of adamgammadex with sugammadex for reversal of rocuronium-induced neuromuscular block.

BACKGROUND: Preliminary clinical trials of adamgammadex, a new cyclodextrin-based selective reversal agent, have demonstrated its efficacy in reversing neuromuscular block by rocuronium. METHODS: This multicentre, randomised, double-blind, positive-controlled, non-inferiority phase III clinical trial compared the efficacy and safety of adamgammadex and sugammadex. We randomised 310 subjects to receive adamgammadex (4 mg kg-1) or sugammadex (2 mg kg-1) at reappearance of the second twitch of the train-of-four (TOF), and standard safety data were collected. RESULTS: For the primary outcome, the proportion of patients with TOF ratio ≥0.9 within 5 min was 98.7% in the adamgammadex group vs 100% in the sugammadex group, with a point estimate and 95% confidence interval (CI) of 1.3% (-4.6%, +1.3%); the lower limit was greater than the non-inferiority margin of -10%. For the key secondary outcome, the median (inter quartile range) time from the start of administration of adamgammadex or sugammadex to recovery of TOF ratio to 0.9 was 2.25 (1.75, 2.75) min and 1.75 (1.50, 2.00) min, respectively. The difference was 0.50 (95% CI: 0.25, 0.50); the upper limit was lower than the non-inferiority margin of 5 min. In addition, there were no inferior results observed in secondary outcomes. Adamgammadex had a lower incidence of adverse drug reactions compared with sugammadex (anaphylactic reaction, recurarisation, decreased heart rate, and laryngospasm; P=0.047). CONCLUSIONS: Adamgammadex was non-inferior to sugammadex with a possible lower incidence of adverse drug reactions compared with sugammadex. Adamgammadex may have a potential advantage in terms of its overall risk-benefit profile. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000039525. Registered October 30, 2020. https://www.chictr.org.cn/showproj.html?proj=56825.

Association between body roundness index and overactive bladder: results from the NHANES 2005-2018.

BACKGROUND AND AIM: An increasing amount of research has indicated obesity greatly affects individuals with overactive bladder (OAB). However, traditional anthropometric methods present challenges in accurately assessing the likelihood of OAB. Hence, this study's objective was to identify the correlation between the body roundness index (BRI) and OAB. METHODS: The research included 12,401 individuals who participated in the National Health and Nutrition Examination Survey spanning 2005-2018. The correlation between BRI and OAB was explored by using weighted multiple logistic regression and weighted restricted cubic spline (RCS). Subgroup analyses showed the associations based on different population types. The study also analyzed the predictive capability of various anthropometric indices, including BRI, body mass index, waist circumference, and weight, in assessing the likelihood of OAB through Receiver-operating characteristic (ROC) curves. RESULTS: An independent positive correlation between OAB and BRI was identified after adjusting for potential confounders in weighted multivariate logistic models[odds ratio (OR) = 1.15, 95% confidence interval (CI), 1.12-1.17]. Weighted RCS analysis found a positive dose-response correlation between OAB and BRI. The effect size of BRI on OAB remained stable across all prespecified subgroups (all P for interactions > 0.05). In ROC analysis, BRI showed better discriminatory ability for OAB compared with other anthropometric measures for both genders (all P < 0.01). The best BRI cutoff for predicting OAB was lower for men (5.151) than for women (5.383), suggesting that men were more susceptible to changes in BRI than women. CONCLUSIONS: This study demonstrated that a raised BRI is correlated with a higher likelihood of OAB. Due to the effectiveness and non-invasiveness of BRI in predicting OAB, it is expected to become the preferred method for early detection and management strategies.

Matrix metalloproteinase-2 inducing COL1A1 synthesis via integrin alpha â ¤ promotes invasion and metastasis of cholangiocarcinoma cells.

INTRODUCTION AND OBJECTIVES: Cholangiocarcinoma (CCA) is characterized by early distant invasion and metastasis, whereas the underlying mechanism is still obscure. Increasing evidence shows that collagen type Ι alpha 1 (COL1A1) is a gene associated with the progression of multiple diseases. Here, we attempted to investigate the role of COL1A1 in CCA. MATERIALS AND METHODS: The expression of COL1A1 between tumor tissues and adjacent normal tissues obtained from CCA patients was detected by Western blot and immunofluorescence, followed by analysis of its clinical significance. Then, the biological effects of COL1A1 overexpression or knockdown on CCA cells were evaluated in vitro and in vivo. Finally, molecular mechanism of COL1A1 in regulating the invasion and metastasis of CCA cells was determined by a series of experiments. RESULTS: COL1A1 expression was significantly higher in CCA pathological tissues than in corresponding adjacent normal tissues. Analysis of 83 CCA patients showed that higher expression of COL1A1 was correlated with poorer patient prognosis. Notably, overexpression or knockdown experiments revealed that COL1A1 contributed to the migration and invasion, as well as epithelial-to-mesenchymal transition (EMT), in CCA cells. Further investigations demonstrated that matrix metalloproteinase-2 (MMP2) promoted COL1A1 upregulation via the integrin alpha Ⅴ pathway, therefore affecting ECM remodelling and inducing EMT in CCA cells. Moreover, COL1A1 expression was positively related to PD-1 and PD-L1 in CCA, and COL1A1 increased PD-L1 expression by activating the NF-κB pathway. CONCLUSIONS: COL1A1 plays an important role in regulating CCA progression and may act as a promising biomarker and therapeutic target for CCA.

Development of a nomogram for predicting nosocomial infections among patients after cardiac valve replacement surgery.

AIMS AND OBJECTIVES: To construct a predictive nomogram of the risk of nosocomial infections among patients after cardiac valve replacement surgery. BACKGROUND: Nosocomial infections are a standout challenge that worsens the prognosis of patients after valve replacement surgery. However, studies on the nomogram of nosocomial infections in these patients have remained scarce. DESIGN: A retrospective cohort study. METHODS: Patients (n = 720) following valve replacement surgery from 2018 to 2019 were selected. LASSO regression and multivariate logistic regression were utilised to ascertain predictors of nosocomial infections. The predictive performance of the nomogram was appraised by calibration and discrimination. Decision and impact curves were used to assess the clinical utility. Internal validation was implemented via 1000 bootstrap samples to mitigate overfitting. TRIPOD guidelines were used in this study. RESULTS: One hundred and fifty one patients (20.97%) experienced nosocomial infections following valve replacement surgery. Heart failure, preoperative anaemia, valve material, American Society of Anesthesiologists score ≥ IV, prolonged duration of surgery, duration of mechanical ventilation ≥ 24 h and indwelling nasogastric tube were predictors of nosocomial infections. Using these variables, we developed a predictive nomogram of the occurrence of nosocomial infections and the internal validation results demonstrated good discrimination and calibration of the nomogram. The clinical decision and impact curve revealed significant clinical utility. CONCLUSIONS: The present study constructed a nomogram for predicting the risk of nosocomial infections in patients following cardiac valve replacement surgery. This nomogram may strengthen the effective screening of patients at high risk of nosocomial infections. RELEVANCE TO CLINICAL PRACTICE: This risk warning tool can assist clinical staff in making decisions and providing individualised infection control measures for patients, which has a significant reference value for clinical practice. NO PATIENT OR PUBLIC CONTRIBUTION: The data for this study were obtained from the hospital database, and the entire process of the study did not involve patient participation.

Observation of Ultrastrong Coupling between Substrate and the Magnetic Topological Insulator MnBi2Te4.

The intrinsic magnetic topological insulator MnBi2Te4 has attracted significant interest recently as a promising platform for exploring exotic quantum phenomena. Here we report that, when atomically thin MnBi2Te4 is deposited on a substrate such as silicon oxide or gold, there is a very strong mechanical coupling between the atomic layer and the supporting substrate. This is manifested as an intense low-frequency breathing Raman mode that is present even for monolayer MnBi2Te4. Interestingly, this coupling turns out to be stronger than the interlayer coupling between the MnBi2Te4 atomic layers. We further found that these low-energy breathing modes are highly sensitive to sample degradation, and they become drastically weaker upon ambient air exposure. This is in contrast to the higher energy optical phonon modes which are much more robust, suggesting that the low-energy Raman modes found here can be an effective indicator of sample quality.

Reconstruction of the central slip insertion of the extensor tendon with the partial slip of the flexor digitorum superficialis tendon.

INTRODUCTION: To introduce the surgical approach and clinical effect of transferring the partial slips of the flexor digitorum superficialis (FDS) tendon to reconstruct the insertion of the central slip of the extensor tendon (CSET) through an established bone tunnel (BT). MATERIALS AND METHODS: From April 2019 to March 2021, nine patients (six males and three females) with the CSET insertion rupture or defect were admitted to the institution and the CSET insertion was reconstructed with partial tendon slips on both sides of the FDS. The active range of motion of the interphalangeal joint of the affected finger was measured by a goniometer, the degree of pain was evaluated by visual analogue scale (VAS), and the grip strength of the affected limb was measured by an electronic hand dynamometer. RESULTS: The average postoperative follow-up was 12 months. No complications occurred. At the last follow-up, six of the patients were very satisfied and three were satisfied with their recovery. CONCLUSION: The reconstruction of the CSET insertion by transferring the partial tendon slips of the FDS seem to be safe and feasible with minimal invasion to the donor tendon. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Enhanced secondary organic aerosol formation during dust episodes by photochemical reactions in the winter in Wuhan.

To investigate the effect of frequently occurring mineral dust on the formation of secondary organic aerosol (SOA), 106 volatile organic compounds (VOCs), trace gas pollutants and chemical components of PM2.5 were measured continuously in January 2021 in Wuhan, Central China. The observation period was divided into two stages that included a haze period and a following dust period, based on the ratio of PM2.5 and PM10 concentrations. The average ratio of secondary organic carbon (SOC) to elemental carbon (EC) was 1.98 during the dust period, which was higher than that during the haze period (0.69). The contribution of SOA to PM2.5 also increased from 2.75% to 8.64%. The analysis of the relationships between the SOA and relative humidity (RH) and the odd oxygen (e.g., OX = O3 + NO2) levels suggested that photochemical reactions played a more important role in the enhancement of SOA production during the dust period than the aqueous-phase reactions. The heterogeneous photochemical production of OH radicals in the presence of metal oxides during the dust period was believed to be enhanced. Meanwhile, the ratios of trans-2-butene to cis-2-butene and m-/p-xylene to ethylbenzene (X/E) dropped significantly, confirming that stronger photochemical reactions occurred and SOA precursors formed efficiently. These results verified the laboratory findings that metal oxides in mineral dust could catalyse the oxidation of VOCs and induce higher SOA production.

Visible transparent mid-infrared broadband absorbers based on gradient refractive indexes and multi-size cavity resonances.

We proposed a multi-layered nanorod structure with the same tilt angle and different diameters, which has high visible transmittance and strong 3-5 µm absorption based on the principles of the gradient of the refractive index and the multi-size cavity resonances. The indium tin oxide (ITO) was selected as the target material to fabricate the structure by using a glancing angle deposition method. The experimental results show that when the deposition angle θ is 80°, swing deposition is successively done with the rotation angle φ of ±8°, ± 5°, ± 3°, and 0° on the surface of the substrate, and the quartz crystal microbalance thicknesses of ITO nanorods are 220 nm for each deposition, the average transmittance is 80.5% in the range of 400-800 nm and the integrated absorption is 86% in the 3-5 µm band. Such a simple, low-cost, and easy-to-fabricate device has potential applications in window stealth materials and other related fields.

3-5 µm mid-infrared broadband absorbers composed of layered ITO nanorod arrays with high visible light transmittance.

A mid-infrared broadband absorber with high visible light transmittance is proposed in this paper. The absorber is composed of layered ITO nanorod arrays with increasing angles fabricated by oblique angle deposition technique. The experimental results show that the average transmittance of the absorber reaches 80% in the 400-800 nm band and the integrated absorption reaches 82.9% in the 3-5 µm band, when the QCM thickness of the first layer of film is 100 nm and the deposition angle θ is 10°, the QCM heights of the second to fifth layers of nanorods are all 330 nm, and their deposition angles are 55°, 68°, 80°, and 87°, respectively. The high transmittance in the visible band is attributed to the gradient of the refractive index. The broadband absorption in the mid-infrared band results from different resonances in the empty cavities with different sizes. Such a simple and large-area absorber has potential applications in window materials and infrared cloaking.

ITO/Si/ITO semi-cone-shell chiral complexes on silicon nanocones with broadband circular dichroism in the mid-infrared wavelength.

This paper proposed ITO/Si/ITO semi-cone-shell chiral complexes on silicon nanocones with broadband CD in the mid-infrared band. The experimental results show that when the deposition angle θ = 45°, the first ITO deposition of ta = 100 nm, the second Si deposition of tb = 200 nm with the azimuth angle unchanged, and the third ITO deposition of tc = 200 nm after rotating the azimuth angle of 60°, the prepared chiral structure has a broadband CD response in the mid-infrared band of 2.5-4 µm. The broadband CD effect is produced by the internal resonance of the three-dimensional open cavity. The cone structure can be regarded as a plurality of planar open resonant rings with different diameters, and these rings resonate at different wavelengths. The experimental results also show that the proposed chiral ITO structure exhibits a better broadband CD response than that of the structure composed of traditional metal Ag. Such a chiral structure provides a new method for the design of CD devices in the mid-infrared band.

Investigation of putative antimicrobial peptides in Carassius gibel, revealing a practical approach to screening antimicrobials.

Antimicrobial peptides (AMPs) and their mimics are rapidly gaining attention as a new class of antimicrobials due to their clinical potential. AMPs are widely distributed throughout nature and participate in the innate host defense. In this study, 18 AMPs, including 3 ß-defensins, 3 hepcidins, 4 liver-expressed antimicrobial peptide 2 (LEAP-2) compounds, 4 g-type lysozymes, 2 c-type lysozymes, and 2 NK-lysins, were identified from the genome of Carassius auratus by a homologous search and were further classified based on their fundamental structural features and molecular phylogeny. C. auratus AMPs were found to be ubiquitously distributed in all tested tissues and showed similar expression profiles, with the exception of ß-defensins, when RT-qPCR was used to investigate the tissue distribution of AMPs in healthy Carassius gibel. In addition, the expression levels of NK-lysin genes in the tested tissues tended to be upregulated upon bacterial and viral infection when representative NK-lysins were chosen to examine their relative expression levels in various tissues. Importantly, the synthetic peptide caNKL2102-119, which targets the functional domain of saposin B in caNK-lysins, could effectively counter Aeromonas hydrophila, Staphylococcus aureus, and Escherichia coli with minimum inhibitory concentration (MIC) values of 3-6 µg/mL, as well as inhibit the proliferation of spring viraemia of carp virus (SVCV). These results provide potential targets for antibiotic-free breeding in the aquaculture industry.

T-lymphoma invasion and metastasis 1 promotes invadopodia formation and is regulated by the PI3K/Akt signaling pathway in hepatocellular carcinoma.

At present, there are still many poorly understood aspects of the mechanisms underlying hepatocellular carcinoma (HCC) invasion and metastasis. Invadopodia are important structures for cancer cell invasion and metastasis. We determined that high T-lymphoma invasion and metastasis 1 (Tiam1) expression is associated with HCC invasion and metastasis and poor patient prognosis after surgery. Gain- and loss-of-function studies confirmed that Tiam1 promotes invadopodia formation in HCC by activating Rac1. A series of biochemical experiments confirmed that this effect is regulated by the PI3K/Akt signaling pathway. We also confirmed that PIP2 facilitates this effect. In summary, these findings reveal that Tiam1 plays an important role in invadopodia formation in HCC.

Nitric oxide detection using principal component analysis spectral structure matching to the UV derivative spectrum.

Ultraviolet (UV) spectroscopy is widely applied in real-time environmental monitoring, especially in diesel vehicle nitrogen monoxide (NO) emissions. However, in field experiments, UV absorption spectrum may exist for different degrees of drifts. Spectral jitters may exist for various reasons such as optical power variation, electrical signal drift, and the refractive index jitters of the optical path for an extended period of time, which causes the detection system to be calibrated. And the pulse xenon lamps as the UV source are characterized by specific emission lines that interfere in spectral analysis directly. For these problems, we proposed the spectral structure matching method based on principal component analysis (PCA), which was compared with the conventional polynomial fitting method to observe feasibility and variability. Further, the UV derivative spectrum was applied to the system appropriately, due to the variation of the absorption peak, and was only related to the target gas by using the above method. We validated our method experimentally by performing the NO UV detection system with the calibration and the comparison test. The results suggested that the calibration relative error was less than 9% and the measurement relative error was less than 6% for this wide range by the proposed processes, which optimized the interference of spectral structures and fluctuation to the system and therefore provided better monitoring. This study may provide an alternative spectral analysis method that is unaffected on the specific emission lines of lamps and is not limited to the spectral region and the target gas.

Emerging Role of Neutrophil Extracellular Traps in Gastrointestinal Tumors: A Narrative Review.

Neutrophil extracellular traps (NETs) are extracellular fibrous networks consisting of depolymerized chromatin DNA skeletons with a variety of antimicrobial proteins. They are secreted by activated neutrophils and play key roles in host defense and immune responses. Gastrointestinal (GI) malignancies are globally known for their high mortality and morbidity. Increasing research suggests that NETs contribute to the progression and metastasis of digestive tract tumors, among them gastric, colon, liver, and pancreatic cancers. This article explores the formation of NETs and reviews the role that NETs play in the gastrointestinal oncologic microenvironment, tumor proliferation and metastasis, tumor-related thrombosis, and surgical stress. At the same time, we analyze the qualitative and quantitative detection methods of NETs in recent years and found that NETs are specific markers of coronavirus disease 2019 (COVID-19). Then, we explore the possibility of NET inhibitors for the treatment of digestive tract tumor diseases to provide a new, efficient, and safe solution for the future therapy of gastrointestinal tumors.

Physicochemical and Colon Cancer Cell Inhibitory Properties of Theabrownins Prepared by Weak Alkali Oxidation of Tea Polyphenols.

Existing studies on the biological activity of theabrownins are not based on their free state but on the complexes of theabrownins, polysaccharides, proteins, and flavonoids. In this study, theabrownins (TBs-C) were prepared by weak alkali oxidation of tea polyphenols. The ultraviolet-visible scanning spectrum of TBs-C showed two characteristic absorption peaks at 203 and 270 nm. The zeta potential of the TBs-C aqueous solution was negative, and the values varied from - 6.26 to -19.55 mV with a solution pH of 3-9. Storage conditions of pH 5.0-7.0 and around 25 °C were beneficial for the physical and chemical stability of the TBS-C solution. Cells were treated with series concentrations and examined by MTT, HE staining, PI immunofluorescence staining, flow cytometry, and real-time PCR to investigate the antiproliferative effect of TBs-C on human colon cancer HT-29 cells. The results showed that TBs-C, particularly at 500 µg/mL, inhibited cell growth. TBs-C induced HT-29 cell apoptosis, as confirmed by morphological changes, nucleus propidium iodide staining, and distributions of the cell cycle. The apoptotic mechanism may be due to the intracellular redox imbalance induced by TBs-C.

p53 haploinsufficiency and increased mTOR signalling define a subset of aggressive hepatocellular carcinoma.

BACKGROUND & AIMS: p53 mutations occur frequently in human HCC. Activation of the mammalian target of rapamycin (mTOR) pathway is also associated with HCC. However, it is still unknown whether these changes together initiate HCC and can be targeted as a potential therapeutic strategy. METHODS: We generated mouse models in which mTOR was hyperactivated by loss of tuberous sclerosis complex 1 (Tsc1) with or without p53 haplodeficiency. Primary cells were isolated from mouse livers. Oncogenic signalling was assessed in vitro and in vivo, with or without targeted inhibition of a single molecule or multiple molecules. Transcriptional profiling was used to identify biomarkers predictive of HCC. Human HCC materials were used to corroborate the findings from mouse models. RESULTS: p53 haploinsufficiency facilitates mTOR signalling via the PTEN/PI3K/Akt axis, promoting HCC tumorigenesis and lung metastasis. Inhibition of PI3K/Akt reduced mTOR activity, which effectively enhanced the anticancer effort of an mTOR inhibitor. ATP-binding cassette subfamily C member 4 (Abcc4) was found to be responsible for p53 haploinsufficiency- and Tsc1 loss-driven HCC tumorigenesis. Moreover, in clinical HCC samples, Abcc4 was specifically identified an aggressive subtype. The mTOR inhibitor rapamycin significantly reduced hepatocarcinogenesis triggered by Tsc1 loss and p53 haploinsufficiency in vivo, as well as the biomarker Abcc4. CONCLUSIONS: Our data advance the current understanding of the activation of the PTEN/PI3K/Akt/mTOR axis and its downstream target Abcc4 in hepatocarcinogenesis driven by p53 reduction and Tsc1 loss. Targeting mTOR, an unexpected vulnerability in p53 (haplo)deficiency HCC, can be exploited therapeutically to treat Abcc4-positive patients with HCC. LAY SUMMARY: Tsc1 loss facilitates the p53 (haplo)insufficiency-mediated activation of the PTEN/Akt/mTOR axis, leading to the elevated expression of Abcc4 to drive HCC tumorigenesis and metastasis in mice. Inhibition of mTOR protects against p53 haploinsufficiency and Tsc1 loss-triggered tumour-promoting activity, providing a new approach for treating an aggressive subtype of HCC exhibiting high Abcc4 expression.

The role of exosomal miR-375-3p: A potential suppressor in bladder cancer via the Wnt/ß-catenin pathway.

miR-375-3p is a significantly downregulated miRNA in bladder cancer (BC). However, its role in BC regulation is still unclear. In this study, we reported that miR-375-3p overexpression inhibited proliferation and migration and promoted apoptosis in BC cells. Frizzled-8 (FZD8) gene is identified as the direct miR-375-3p targeting gene. miR-375-3p blocks the Wnt/ß-catenin pathway and downstream molecules Cyclin D1 and c-Myc by inhibiting the expression of FZD8 directly, it could increase caspase 1 and caspase 3 expression and promote T24 cell apoptosis as well. miR-375-3p also showed a significant inhibitory effect in vivo in bladder tumor-bearing nude mice, as demonstrated by the reduced tumor volume and Ki67 proliferation index in tumor tissue. Collectively, miR-375-3p is a suppressor of BC that inhibits proliferation and metastasis, and promotes apoptosis in BC cells as well as suppresses tumor growth in a T24 xenograft mouse model, which could be used as a potential therapeutic approach for BC in future.

The 14-day repeated-dose toxicity study of a fixed-dose combination, QXOH/levobupivacaine, via subcutaneous injection in beagle dogs.

QXOH-Levobupivacaine (LB) is a fixed-dose combination of 35-mM QXOH and 10-mM LB. It was developed for perioperative analgesia because of its long-acting analgesic effect. The purpose of this study was to evaluate the potential toxicity of QXOH-LB in beagle dogs in accordance with the Guidance on the repeated-dose toxicity published by the China Food and Drug Administration. Groups of five male and five female beagle dogs received normal saline, QXOH-LB (2, 4, and 8 mg/kg, calculated as QXOH), QXOH (2, 4, and 8 mg/kg), or LB (2 mg/kg, equals the concentration of LB in 8-mg/kg QXOH-LB group) at the volume of 1 mL/kg once per day for 14 days through subcutaneous injection. No mortality was observed. Dogs in the control group as well as animals treated with 2-mg/kg QXOH or QXOH-LB exhibited normal behaviors. Clinical signs of toxicity in dogs treated with 4 and 8 mg/kg of QXOH or QXOH-LB included decreased activity, unsteady gait, jerks, tremors, vocalization, emesis, ataxia, lateral/sternal recumbency, deep/rapid respiration, and gasping. Additionally, neurological function was found to be affected by QXOH and QXOH-LB at the doses of 4 and 8 mg/kg. All clinical signs were recovered within 24 h. The no-observed-adverse-effect level of QXOH and QXOH-LB was considered to be 2 mg/kg. Toxicokinetic data showed that exposure to QXOH and LB increased as QXOH-LB doses were increased from 4 to 8 mg/kg. There was no evidence of drug accumulation or any effect of gender.

The 14-day repeated-dose toxicity studies of a fixed-dose combination, QXOH/levobupivacaine, via subcutaneous injection in mice.

QXOH-LB, a fixed-dose combination (35 mM QXOH and 10 mM levobupivacaine) has been shown to induce a long duration of local anesthesia in animal efficacy testing, which indicates potential for postoperative pain management. In this study, we evaluated the potential toxicity of QXOH-LB in NIH mice under the Guidance on the repeated-dose toxicity published by the China Food and Drug Administration. Mice (n = 30 per sex per group) were subcutaneously injected 5, 10, 20 mg/kg QXOH-LB, 5, 10, 20 mg/kg QXOH, and 5 mg/kg levobupivacaine (LB) once a day for 14 days with sacrifice of main study animals; remaining mice (n = 10 per sex per group) were monitored for an additional 4-week recovery period. Mice in the 10 and 20 mg/kg QXOH, and 20 mg/kg QXOH-LB died, which was considered due to excessive respiratory inhibition. The doses of 10 mg/kg QXOH-LB and 5 mg/kg QXOH were well tolerated without any clinical signs of toxicity. Therefore, the no-observed-adverse-effect level (NOAEL) of QXOH-LB and QXOH was considered to be 10 and 5 mg/kg/day, respectively. In the dose range from 5 to 20 mg/kg, the exposure of QXOH and LB in QXOH-LB was equal to each agent used alone at the same dose in NIH mice. There was no gender difference on exposure and no evidence of accumulation.