Impact of homocysteine on acute ischemic stroke severity: possible role of aminothiols redox status.

BACKGROUND: Acute ischemic stroke (AIS) is one of the most common cerebrovascular diseases which accompanied by a disruption of aminothiols homeostasis. To explore the relationship of aminothiols with neurologic impairment severity, we investigated four aminothiols, homocysteine (Hcy), cysteine (Cys), cysteinylglycine (CG) and glutathione (GSH) in plasma and its influence on ischemic stroke severity in AIS patients. METHODS: A total of 150 clinical samples from AIS patients were selected for our study. The concentrations of free reduced Hcy (Hcy), own oxidized Hcy (HHcy), free reduced Cys (Cys), own oxidized Cys (cysteine, Cyss), free reduced CG (CG) and free reduced GSH (GSH) were measured by our previously developed hollow fiber centrifugal ultrafiltration (HFCF-UF) method coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration ratio of Hcy to HHcy (Hcy/HHcy), Cys to Cyss (Cys/Cyss) were also calculated. The neurologic impairment severity of AIS was evaluated using National Institutes of Health Stroke Scale (NIHSS). The Spearman correlation coefficient and logistic regression analysis was used to estimate and perform the correlation between Hcy, HHcy, Cys, Cyss, CG, GSH, Hcy/HHcy, Cys/Cyss and total Hcy with NIHSS score. RESULTS: The reduced Hcy and Hcy/HHcy was both negatively correlated with NIHSS score in AIS patients with P = 0.008, r=-0.215 and P = 0.002, r=-0.249, respectively. There was no significant correlation of Cys, CG, GSH, HHcy, Cyss, Cys/Cyss and total Hcy with NIHSS score in AIS patients with P value > 0.05. CONCLUSIONS: The reduced Hcy and Hcy/HHcy, not total Hcy concentration should be used to evaluate neurologic impairment severity of AIS patient.

A novel dual-epigenetic inhibitor enhances recombinant monoclonal antibody expression in CHO cells.

Epigenetic regulation plays a central role in the regulation of a number of cellular processes such as proliferation, differentiation, cell cycle, and apoptosis. In particular, small molecule epigenetic modulators are key elements that can effectively influence gene expression by precisely regulating the epigenetic state of cells. To identify useful small-molecule regulators that enhance the expression of recombinant proteins in Chinese hamster ovary (CHO) cells, we examined a novel dual-HDAC/LSD1 inhibitor I-4 as a supplement for recombinant CHO cells. Treatment with 2 µM I-4 was most effective in increasing monoclonal antibody production. Despite cell cycle arrest at the G1/G0 phase, which inhibits cell growth, the addition of the inhibitor at 2 µM to monoclonal antibody-expressing CHO cell cultures resulted in a 1.94-fold increase in the maximal monoclonal antibody titer and a 2.43-fold increase in specific monoclonal antibody production. In addition, I-4 significantly increased the messenger RNA levels of the monoclonal antibody and histone H3 acetylation and methylation levels. We also investigated the effect on HDAC-related isoforms and found that interference with the HDAC5 gene increased the monoclonal antibody titer by 1.64-fold. The results of this work provide an effective method of using epigenetic regulatory strategies to enhance the expression of recombinant proteins in CHO cells. KEY POINTS: • HDAC/LSD1 dual-target small molecule inhibitor can increase the expression level of recombinant monoclonal antibodies in CHO cells. • By affecting the acetylation and methylation levels of histones in CHO cells and downregulating HDAC5, the production of recombinant monoclonal antibodies increased. • It provides an effective pathway for applying epigenetic regulation strategies to enhance the expression of recombinant proteins.

Application of Tranexamic Acid in Shoulder Arthroscopic Surgery: A Randomised Controlled Trial.

Objective To explore the optimal administration route of tranexamic acid (TXA) in shoulder arthroscopic surgery. Methods Patients undergoing arthroscopic rotator cuff repair were randomly divided into four groups: control group (without TXA treatment), intravenous group (TXA was intravenously administered 10 minutes before surgery), irrigation group (TXA was added to the irrigation fluid during subacromial decompression and acromioplasty), and intravenous plus irrigation group (TXA was applied both intravenously and via intra-articular irrigation). The primary outcome was visual clarity assessed with visual analog scale (VAS) score, and the secondary outcomes included irrigation fluid consumption and time to subacromial decompression and acromioplasty procedure. Results There were 134 patients enrolled in the study, including 33 in the control group, 35 in the intravenous group, 32 in the irrigation group, and 34 in the intravenous plus irrigation group. The median and interquartile range of VAS scores for the intravenous, irrigation, and intravenous plus irrigation groups were 2.70 (2.50, 2.86) (Z = -3.677, P = 0.002), 2.67 (2.50, 2.77) (Z = -3.058, P < 0.001), and 2.91 (2.75, 3.00) (Z = -6.634, P < 0.001), respectively, significantly higher than that of the control group [2.44 (2.37, 2.53)]. Moreover, the control group consumed more irrigation fluid than the intravenous group, irrigation group, and intravenous plus irrigation group (all P < 0.05). The intravenous plus irrigation group consumed less irrigation fluid than either the intravenous group or the irrigation group (both P < 0.001). There was no difference in subacromial decompression and acromioplasty operative time among the four groups. Conclusion TXA applied both topically and systematically can improve intraoperative visual clarity, and the combined application is more effective.

Microplastics in take-out food: Are we over taking it?

Take-out food has become increasingly prevalent due to the fast pace of people's life. However, few study has been done on microplastics in take-out food. Contacting with disposable plastic containers, take-out food may be contaminated with microplastics. In the present study, abundance and characteristics of microplastics in total of 146 take-out food samples including solid food samples and beverage samples (bubble tea and coffee) were determined and identified. The mean abundance of microplastics in take-out food was 639 items kg-1, with the highest value in rice and the lowest value in coffee. Fragments shape, transparent color and sizes ≤ 500 µm were the main characteristics of microplastics in those food, and polyethylene was the main polymer type. Our results indicated that microplastics in take-out food was influenced by food categories and cooking methods, as well as food packaging materials. Approximately 170-638 items of microplastics may be consumed by people who order take-out food 1-2 times weekly.

A Direct Injection Technique to Improve Biosafety to Analyze Levetiracetam Concentrations in Human Serum and Its Application in Therapeutic Drug Monitoring.

BACKGROUND: With the outbreak of COVID-19, it has become very important to improve biosafety measures taken by medical staff. Fewer pretreatment steps correspond to lower chances of infection. The authors established a direct injection technique to analyze levetiracetam (LEV) concentrations in human serum and studied its application in therapeutic drug monitoring. METHODS: Serum samples were prepared by hollow fiber centrifugal ultrafiltration and the filtrate was directly injected into a ultra-high performance liquid chromatography apparatus (Waters UPLC BEH C18 column: 50 × 2.1 mm, 1.7 µm) for analysis. The mobile phase consisted of acetonitrile and water (8:92) at a flow rate of 1.0 mL/min. The column temperature was maintained at 30°C. The detected wavelength was 210 nm. RESULTS: A linear relationship was obtained for LEV from 0.625 to 80 mcg/mL (r2 = 0.999). The limit of detection for the analysis of LEV was 0.125 mcg/mL. The analysis time was shortened to 4 minutes. The recovery rate of LEV based on the current method was 96.6%-100.1%, whereas the absolute recovery rate was 93.2%-96.8%. The relative SD of intraday and interday precision was <7.3%. Stability was achieved at room temperature for 24 hours after 3 freeze-thaw cycles and at -80°C for 21 days. The method was successfully applied to determine LEV concentrations in the serum of 19 patients. CONCLUSIONS: The present method is simple, accurate, and sensitive, and can improve biosafety with the direct injection technique. It is suitable for the analysis of LEV concentrations in therapeutic drug monitoring.

A simple and accurate HFCF-UF method for the analysis of homocysteine, cysteine, cysteinyl-glycine, and glutathione in human blood.

The presence of reduced aminothiols, including homocysteine (Hcy), cysteine (Cys), cysteinyl-glycine (CG), and glutathione (GSH), is significantly increased in the pathological state. However, there have been no reports on the relationship between reduced aminothiols (Hcy, Cys, CG, and GSH) and different genders, ages, and drug combinations in human blood. The accurate quantification of these reduced thiols in biological fluids is important for monitoring some special pathological conditions of humans. However, the published methods typically not only require cumbersome and technically challenging processing procedures to ensure reliable measurements, but are also laborious and time-consuming, which may disturb the initial physiological balance and lead to inaccurate results. We developed a hollow fiber centrifugal ultrafiltration (HFCF-UF) method for sample preparation coupled with a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method and used it to determine four reduced aminothiols (Hcy, Cys, CG, and GSH) in human blood for the first time. A total of 96 clinical patients were enrolled in our study. The influence of different genders, ages, and drug combinations on the levels of four reduced thiols in human blood was also discussed by SPSS 24.0. The sample preparation was simplified to a single 5 min centrifugation step in a sealed system that did not disturb the physiological environment. The validation parameters for the methodological results were excellent. The procedure was successfully applied to monitoring the concentrations of four reduced aminothiols (Hcy, Cys, CG, and GSH) in 96 clinical blood samples. There were no significant differences in Hcy, Cys, CG, or GSH for the different genders, ages, or combinations with methotrexate or vancomycin (P > 0.05). However, there was a significant increase in Hcy concentration in patients treated with valproic acid who were diagnosed with epilepsy (p=0.0007). It is advisable to measure reduced Hcy level in patients taking valproic acid. The developed HFCF-UF method was simple and accurate. It can be easily applied in clinical research to evaluate oxidative stress in further study.

Clinical value of vestibular-evoked myogenic potential tests in patients with sudden sensorineural hearing loss.

BACKGROUND: This study aims to investigate the clinical value of two kinds of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss (SSNHL). METHODS: A total of 82 patients were divided into two groups: vertigo group and non-vertigo group. All patients underwent examinations for pure tone hearing thresholds, middle ear analysis, the videonystagmography, caloric tests, and vestibular-evoked myogenic potentials elicited from the sternocleidomastoid and extraocular muscle. In addition, 30 healthy subjects were selected as the control group. RESULTS: For the 30 healthy subjects, the average latency of p13 and n23 of the cervical vestibular evoked myogenic potentials (cVEMPs) were 13.13 ± 2.89 ms and 23.51 ± 3.25 ms, respectively, and the bilateral amplitude asymmetry rate ranged within 0.05-0.31. The average latency of n10 of the ocular vestibular evoked myogenic potentials (oVEMPs) was 10.13 ± 0.48 ms. The average amplitude of the n10-p15-wave was 5.58 ± 0.65 µV. Among the 35 vertigo patients with SSNHL, 27 patients had normal cVEMP and oVEMP examination results, five patients had abnormal oVEMP examination results, and five patients had abnormal cVEMP examination results. The latency and amplifier of oVEMPs and cVEMPs were within the normal range in 47 SSNHL patients without vertigo. The chi-square value was 5.647, the P-value was equal to 0.017, and the difference was statistically significant at a confidence interval of 95%. CONCLUSIONS: OVEMPs and cVEMPs can be used evaluate the vestibular nerve function of SSNHL patients with vertigo.

Occurrence and risk assessment of p-phenylenediamines and their quinones in aquatic environment: From city wastewater to deep sea.

p-Phenylenediamines (PPDs) and PPD-derived quinones (PPD-Qs) have been considered emerging pollutants recently. Their available data on sediment and sewage sludge are limited, especially the ecological risks. Here, typical PPDs and PPD-Qs were measured in the sludge of wastewater treatment plants and surface sediment of a developed river basin (including reservoirs, estuaries, and rivers) and deep-sea troughs. The total concentrations of PPDs (∑PPD) were highest in sludge (range: 9.06-248 ng g-1), followed by surface sediment of the Dongjiang River basin, China (3.33-85.3 ng g-1), and lowest in sediment of the Okinawa Trough (0.01-7.46 ng g-1). The median value of ∑PPD in surface sediment of rivers (9.54 ng g-1) was higher than those in reservoirs (4.28 ng g-1) and estuaries (5.26 ng g-1). N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) was the major congener in all samples, accounting for over 60 % of ∑PPD. For quinones, 6PPD-Q and IPPD-Q were frequently detected in sludge, only trace 6PPD-Q was detected in the sediment of estuaries (nd-0.62 ng g-1) and rivers (nd-5.24 ng g-1), and both of them were absent from the sediment of the Okinawa Trough. The occurrence of PPDs in the trough may be the in-situ release of microplastics, and due to the low-light and weak alkaline conditions of deep-sea water, quinones may hardly photodegrade from PPDs. The PPD concentrations in sludge were positively correlated with local GDP, and the annual PPD emission from sludge will exceed 1370 kg in China. The results of ecological risk assessments indicated low risks for PPDs in sludge-amended soil, median risks for several PPDs in river sediment, but median to high risks for 6PPD-Q contamination sludge-amended soil. For the first time, we explored the potential environmental risk of PPDs and related quinones in sludge used as a soil conditioner.

Widespread phthalate esters and monoesters in the aquatic environment: Distribution, bioconcentration, and ecological risks.

Field research on phthalate monoesters (MPEs) and their relationships with phthalate esters (PAEs) is limited, especially in wild fishes. Here, PAEs and MPEs were measured in surface water, sediment, and wild fish collected from a representative river basin with high economic development. Several metabolites of emerging plasticizers, such as mono(3,5,5-trimethyl-1-hexyl) phthalate and mono(6-oxo-2-propylheptyl) phthalate, have already existed in fish with high detection frequencies (95 % and 100 %). Monobutyl phthalate and mono(2-ethylhexyl) phthalate were the predominant MPEs in fish and natural environment (surface water and sediment), while bis(2-ethylhexyl) phthalate was the most abundant PAEs in all matrices. The total concentrations (median) of 9 PAEs and 16 MPEs were 5980 and 266 ng/L in water, 231 and 10.6 ng/g (dw) in sediment, and 209 and 32.5 ng/g (ww) in fish, respectively. The occurrence of MPEs was highly related to their parent PAEs, with similar spatial distribution characteristics in the aquatic environments. Moreover, municipal wastewater discharge was recognized as the main source of MPEs in the research area. Fish species can accumulate targeted chemicals, and it seems more MPEs were from the PAE degradation in fish other than the direct uptake of MPEs in water. Parent PAEs showed higher ecological risk than their corresponding metabolites.

Development of an hollow fiber solid phase microextraction method for the analysis of unbound fraction of imatinib and N-desmethyl imatinib in human plasma.

Therapeutic drug monitoring (TDM) of imatinib (IM) in cancer therapy offers the potential to improve treatment efficacy while minimizing toxicity. There was a significant correlation between unbound concentration and clinical response and toxicity, compared with total plasma concentrations, and the quantification of unbound IM and its metabolite, N-desmethyl imatinib (NDI) are of interest for TDM. However, traditional unbound drug separation methods have shortcomings, especially are susceptible to non-specific binding (NSB) of drugs to the polymer-constructed components of filter membranes, which are difficult to avoid at present. Hence it is necessary to developed a reliable separation method for the analysis of the unbound fraction of IM and NDI in TDM. We developed and validated an hollow fiber solid phase microextraction (HF-SPME) method coupled with high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) that to measure unbound IM and NDI concentration in human plasma. It used the NSB phenomenon and solve the NSB problem. The preparation procedure only involves a common vortex and ultrasonication without dilution of samples and modification of membrane. A total of 50 chronic myeloid leukemia (CML) patients were enrolled in our study. The relationship between the unbound and total concentrations for IM and NDI, as well as the concentration ratios of NDI to IM in 50 clinical plasma samples were investigated. The extraction recovery is high to 95.5-106 % with validation parameters for the methodological results were all excellent. There were both a poor linear relationship between the unbound and total concentrations for IM (r2=0.504) and NDI (r2=0.201) in 50 clinical plasma samples. The unbound concentration ratios of NDI to IM varied widely in CML patients. The determination of unbound IM and NDI concentration is meaningful and necessary. The developed HF-SPME method is simple, accurate and precise that could be used to measure unbound IM and NDI concentration in clinical TDM.

Overexpression of YTHDF3 increases the specific productivity of the recombinant protein in CHO cells by promoting the translation process.

Due to their high-quality characteristics, Chinese hamster ovary (CHO) cells have become the most widely used and reliable host cells for the production of recombinant therapeutic proteins in the biomedical field. Previous studies have shown that the m6A reader YTHDF3, which contains the YTH domain, can affect a variety of biological processes by regulating the translation and stability of target mRNAs. This study investigates the effect of YTHDF3 on transgenic CHO cells. The results indicate that stable overexpression of YTHDF3 significantly enhances recombinant protein expression without affecting host cell growth. Transcriptome sequencing indicated that several genes, including translation initiation factor, translation extension factor, and ribosome assembly factor, were upregulated in CHO cells overexpressing YTHDF3. In addition, cycloheximide experiments confirmed that YTHDF3 enhanced transgene expression by promoting translation in CHO cells. In conclusion, the findings in this study provide a novel approach for mammalian cell engineering to increase protein productivity by regulating m6A.

A more accurate indicator to evaluate oxidative stress in rat plasma with osteoporosis.

Background: oxidative stress is linked to various human diseases which developed into the idea of "disrupted redox signaling". Osteoporosis (OP) is a chronic skeletal disorder characterized by low bone mineral density and deterioration of bone microarchitecture among which estrogen deficiency is the main cause. Lack of estrogen leads to the imbalance between oxidation and anti-oxidation in patients, and oxidative stress is an important link in the pathogenesis of OP. The ratio of the reduced to the oxidized thiols can characterize the redox status. However, few methods have been reported for the simultaneous determination of reduced forms and their oxidized forms of thiols in plasma. Methods: we developed a hollow fiber centrifugal ultrafiltration (HFCF-UF) method for sample preparation and validated a high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method to determine two reduced forms of thiols-homocysteine (Hcy), cysteine (Cys) levels and their respective oxidized compounds, homocystine (HHcy) and cystine (Cyss) in rat plasma simultaneously for the first time. Thirty-six female rats were randomly divided into three groups: normal control (NC), oxidative stress (ovariectomy, OVX) and ovariectomy with hydrogen-rich saline administration (OVX + HRS). Results: the validation parameters for the methodological results were within the acceptance criteria. There were both significant differences of Hcy/HHcy (Hcy reduced/oxidized) and Cys/Cyss (Cys reduced/oxidized) in rat plasma between three groups with both p < 0.05 and meanwhile, the p values of malondialdehyde, superoxide dismutase and glutathione peroxidase were all less than 0.01. The value of both Hcy/HHcy and Cys/Cyss were significantly decreased with the change of Micro-CT scan result of femoral neck in OVX group (both the trabecular thickness and trabecular number significantly decreased with a significant increase of trabecular separation) which demonstrate OP occurs. The change of Hcy/HHcy is more obvious and prominent than Cys/Cyss. Conclusions: the Hcy/HHcy and Cys/Cyss could be suitable biomarkers for oxidative stress and especially Hcy/HHcy is more sensitive. The developed method is simple and accurate. It can be easily applied in clinical research to further evaluate the oxidative stress indicator for disease risk factors.

Phthalate exposure and DNA oxidative damage in young people of takeaway food lovers.

Numerous studies have demonstrated the ubiquitous of phthalates in materials of food and food packaging, and the effects of regular eating takeaway food for a long time on human health and phthalate exposure levels were not fully investigated. A total of 288 college students who love eating takeaway food were recruited to explore phthalate exposure and oxidative stress, by measuring metabolites of traditional or alternative phthalates and 8-hydroxydeoxyguanosine (8-OHdG, a biomarker of DNA oxidative damage) in their urine samples. Both traditional and alternative phthalates were highly detected. Based on weekly frequency of takeaway eating collecting from questionnaire, the students were divided into four groups including level 1 (L1, < 3 times), level 2 (L2, 3-7 times), level 3 (L3, 8-12 times) and level 4 (L4, > 12 times). The total concentrations of all phthalate metabolites were 42.5-893 ng/mL in all students, which were significantly different among four groups, with the lowest level in L1 (p < 0.05). Checking with the generalized linear model (L1 as the reference), the concentrations of most phthalate metabolites increased 12.0-144% in L2 and L3 compared with those in L1. For each group increase, the concentrations of total metabolites, and metabolites of high and low molecular weight phthalates will increase by 0.156%, 0.128%, and 0.142%, respectively. Besides, levels of 8-OHdG (0.639-33.7 ng/mL) were positively correlated with phthalate daily exposure doses. The each increase of a percentage unit of daily exposure of phthalates, the concentrations of 8-OHdG will increase by 0.258-0.405%. However, levels of 8-OHdG were not significantly different among the four groups. The alternative phthalates have already entered the body of Chinese young people. Our results indicated the regular consumption of takeaway food (e.g., more than three times per week) may increase the chance of exposure to certain phthalates, and may not significantly increase the levels of DNA oxidative damage, unless exposed to other pollutants such as phthalates.

Analysis of free concentrations of lamotrigine and active oxcarbazepine metabolite in clinical patients by hollow-fiber centrifugal ultrafiltration.

Aim: To establish a simple and accurate method to explore the correlation between free and total concentrations of lamotrigine (LTG) and the active oxcarbazepine metabolite monohydroxy derivative (MHD) (10,11-dihydro-10-hydroxycarbamazepine) in clinical patients. Materials & methods: Serum samples were prepared by hollow-fiber centrifugal ultrafiltration and then injected into UPLC for analysis. Results: Absolute recovery was as high as approximately 90.1-98.6% with excellent precision (relative standard deviation <6.7%). Analysis time was reduced to 5 min. There were significant individual differences in the protein binding rates of both LTG and MHD that were probably due to the use of different clinical patients. Conclusion: Free concentrations of LTG and MHD cannot be estimated by total concentration in specific clinical patients. Free drug monitoring of LTG and MHD in clinical therapeutic drug monitoring is important and essential.

Phthalate metabolites: Characterization, toxicities, global distribution, and exposure assessment.

Phthalates are plasticizers in various products and regarded as endocrine disruptors due to their anti-androgen effects. Environmental occurrence and toxicities of parent phthalates have been widely reported, while the current state of knowledge on their metabolites is rarely summarized. Based on the available literature, the present review mainly aims to 1) characterize the potential metabolites of phthalates (mPAEs) using the pharmacokinetics evidences acquired via animal or human models; 2) examine the molecular and cellular mechanism involved in toxicity for mPAEs; 3) investigate the exposure levels of mPAEs in different human specimens (e.g., urine, blood, seminal fluid, breast milk, amniotic fluid and others) across the globe; 4) discuss the models and related parameters for phthalate exposure assessment. We suggest there is subtle difference in toxic mechanisms for mPAEs compared to their parent phthalates due to their alternative chemical structures. Human monitoring studies performed in Asia, America and Europe have provided the population exposure baseline levels for typical phthalates in different regions. Urine is the preferred matrix than other specimens for phthalate exposure study. Among ten urinary mPAEs, the largest proportions of di-(2-ethylhexyl) phthalate (DEHP) metabolites (40%), monoethyl phthalate (mEP) (43%) and DEHP metabolites/mEP (both 29%) were observed in Asia, America and Europe respectively, and mono-5-carboxy-2-ethypentyl phthalate was the most abundant compounds among DEHP metabolites. Daily intakes of phthalates can be accurately calculated via urinary mPAEs if the proper exposure parameters were determined. Further work should focus on combining epidemiological and biological evidences to establish links between phthalates exposure and biological phenotypes. More accurate molar fractions (FUE) of the urinary excreted monoester related to the ingested diesters should be collected in epidemiological or pharmacokinetic studies for different population.

Relationship Between the Free and Total Methotrexate Plasma Concentration in Children and Application to Predict the Toxicity of HD-MTX.

High-dose methotrexate (HD-MTX) can be highly effective as well as extremely toxic. Many drug molecules can bind to plasma proteins to different extents in vivo, whereas only the free drug can reach the site of action to exert a pharmacological effect and cause toxicity. However, free MTX concentrations in plasma have not been reported. Traditional analyses of free drugs are both cumbersome and inaccurate. We collected 92 plasma samples from 52 children diagnosed with ALL or NHL or other lymphomas that were treated with HD-MTX. The hollow fiber centrifugal ultrafiltration (HFCF-UF) was used to prepare plasma samples for analysis of the free MTX concentration. Protein precipitation was employed to measure the total MTX concentration. The HFCF-UF is a simple method involving a step of ordinary centrifugation; the validation parameters for the methodological results were satisfactory and fell within the acceptance criteria. A linearity coefficient r 2 of 0.910 was obtained for the correlation between the free and total MTX plasma concentrations in 92 plasma samples. However, the free and total MTX concentrations was only weakly correlated in 16 clinical plasma specimens with total MTX concentrations >2 µmol L-1 (r 2 = 0.760). Both the free and total MTX concentrations at 42 h were negatively correlated with the creatinine clearance (CCr) level (P = 0.023, r = -0.236 for total MTX and P = 0.020, r = -0.241for free MTX, respectively). The free MTX concentration could not be accurately estimated from the total MTX concentration for patients with high MTX levels which are conditions under which toxic reactions are more likely to occur. High plasma MTX levels could become a predictor of the occurrence of MTX nephrotoxicity to draw people's attention. The proposed HFCF-UF method is a simple and accurate way to evaluate efficacy and toxicity in clinical therapeutic drug monitoring.

Triplanar Chevron Osteotomy: A Newly Proposed Method to Treat Hallux Valgus Deformities.

OBJECTIVE: To present a novel method called triplanar chevron osteotomy to treat hallux valgus (HV). METHODS: This is a retrospective study. In this study, the CT data of HV patients with painful callosities were evaluated retrospectively between 1 June 2018 and 1 June 2020. CT data from 49 consecutive patients (59 feet) with HV were evaluated. The average age at the time of surgery was 49.6 years (range, 30-63 years). The apex of the chevron osteotomy procedure was located at the center of the first metatarsal and was defined as the line formed by the central point perpendicular to the fourth metatarsal bone. The cut planes of the plantarward oblique chevron osteotomy (POCO) were defined as follows: chevron osteotomy along with 20° of plantarward obliquity. The triplanar osteotomy incision was made using the POCO method, with the direction inclined by 10° distally. The intermetatarsal angle (IMA), the HV angle (HVA), the projection of the second metatarsal (PSM), the metatarsal protrusion index (MPI), and the metatarsal protrusion distance (MPD) were all calculated before and after the operations. The length of the first metatarsal was measured and calculated with an equation. RESULTS: The results showed that the HVA was significantly decreased after surgery (32.7° ± 4.6° vs 14.9° ± 2.1°, t = 25.583, P < 0.001) in the triplanar, traditional, and POCO groups. The IMA was also significantly decreased (14.7° ± 2.0°) compared with the results before surgery (8.0° ± 1.1°, t = 22.739, P < 0.001) in these groups. Compared with traditional osteotomy and POCO, there were no differences in correcting deformities on axial planes for the HVA (14.5° ± 1.7° vs 14.9° ± 2.1°, t = 1.835, P = 0.072) and IMA (8.1° ± 1.1° vs 8.0° ± 1.1°, t = -0.97, P = 0.336). There was a statistically significant decrease following surgery in terms of the PSM, MPI, and MPD after triplanar osteotomy. The length of the first metatarsal increased (10.9 ± 1.3 mm), as measured through three-dimensional images in the triplanar osteotomy group. The length was calculated as follows: H = L2 * Tan θ ≈ L/COS ß * Tan θ. CONCLUSION: The new triplanar osteotomy technique is safe and effective for treating HV, and in simulation experiments reveals potential benefits of correction and preventing transfer metatarsalgia.

Bone Material Properties of Human Phalanges Using Vickers Indentation.

OBJECTIVE: To investigate the microhardness distribution throughout the human hand phalanges using the Vickers method, which can be used to directly evaluate the bone mechanical properties at tissue level and provide an alternative means to investigate bone quality. METHODS: The phalanges bones involved in this study were collected from three healthy donors; fresh-frozen right limbs were used. The phalanges bones were dissected and cut into 3-mm thick slices perpendicular to the long axis in the phalanges base, the phalanges shaft, and the phalanges head with a low-speed saw and then the slices were polished with sandpaper. A microindenter fitted with a Vickers indenter point was used to measure the Vickers hardness in the plantar, dorsal, medial, and lateral sites of cortical bone in metatarsal shaft and trabecular bone in the metatarsal base and head. The indentation load and dwell time was set to 50 g and 12 s for both the cortical and cancellous tissues in this study. For each site or region, five valid values were recorded and averaged as the Vickers hardness for the site or region. RESULTS: In total, 96 bone slices were harvested from the base, shaft, and head of the 15 phalanges and 1920 indentations were performed. In general, the Vickers hardness in phalanges was 34.11 ± 7.95 HV. For the 5 phalanges, the 3rd phalanx showed the highest hardness (36.74 ± 7.10 HV), closely followed by the 1st (36.46 ± 5.96 HV) and 2nd (35.28 ± 6.52 HV) phalanx. The hardness in the 4th (31.90 ± 9.15 HV) and 5th (31.19 ± 8.22 HV) phalanx were significantly lower than in the other 3 phalanges. The hardness in the phalanx shaft (38.52 ± 6.67 HV) was significantly higher than that in both the base (30.73 ± 7.46 HV) and head (30.64 ± 6.81 HV) of the phalanx (F = 300.7, P = 0.000); no statistic difference existed between the base and head of the phalanx (P = 0.996). The Vickers hardness in the proximal, middle, and distal phalanx showed statistical difference in Vickers hardness (F = 19.278, P = 0.000). The proximal phalanx showed higher Vickers hardness than the middle phalanx in the 2nd to 5th phalanges (P = 0.002). CONCLUSION: This study reported on the Vickers hardness distribution of the human phalanges bone and provides the theoretical basis of differences in hardness, which will benefit the placement of plates and screws in orthopaedic surgery and contribute to the research on ideal artificial bones and 3D-printed orthopaedic implants with inner gradient distribution of hardness.

Strigolactones: a plant phytohormone as novel anti-inflammatory agents.

Strigolactones (SLs) are a novel class of plant hormones with enormous potential for the prevention and treatment of inflammation. To further investigate the anti-inflammatory activities of SLs, a representative SL, GR24, and the reductive products of its D-ring were synthesized and their anti-inflammatory activities were fully evaluated on both in vitro and in vivo models. Among these compounds, the two most active optical isomers (2a and 6a) demonstrated strong inhibitory activity on the release of inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) by blocking the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways; they also greatly inhibited the migration of neutrophils and macrophages in fluorescent protein labeled zebrafish larvae. These results identified the promising anti-inflammatory effects of SLs, and suggested that both the absolute configuration of SL and the α,ß-unsaturated D-ring structure are essential for the observed anti-inflammatory activity.

Design and prediction of new anticoagulants as a selective Factor IXa inhibitor via three-dimensional quantitative structure-property relationships of amidinobenzothiophene derivatives.

Factor IXa (FIXa), a blood coagulation factor, is specifically inhibited at the initiation stage of the coagulation cascade, promising an excellent approach for developing selective and safe anticoagulants. Eighty-four amidinobenzothiophene antithrombotic derivatives targeting FIXa were selected to establish three-dimensional quantitative structure-activity relationship (3D-QSAR) and three-dimensional quantitative structure-selectivity relationship (3D-QSSR) models using comparative molecular field analysis and comparative similarity indices analysis methods. Internal and external cross-validation techniques were investigated as well as region focusing and bootstrapping. The satisfactory q (2) values of 0.753 and 0.770, and r (2) values of 0.940 and 0.965 for 3D-QSAR and 3D-QSSR, respectively, indicated that the models are available to predict both the inhibitory activity and selectivity on FIXa against Factor Xa, the activated status of Factor X. This work revealed that the steric, hydrophobic, and H-bond factors should appropriately be taken into account in future rational design, especially the modifications at the 2'-position of the benzene and the 6-position of the benzothiophene in the R group, providing helpful clues to design more active and selective FIXa inhibitors for the treatment of thrombosis. On the basis of the three-dimensional quantitative structure-property relationships, 16 new potent molecules have been designed and are predicted to be more active and selective than Compound 33, which has the best activity as reported in the literature.