[Recommendations for the diagnosis and treatment of connective tissue disease associated pulmonary arterial hypertension in China]

Pulmonary arterial hypertension (PAH) is a clinicopathological syndrome caused by the increase of pulmonary artery, and it is the most serious complication of connective tissue disease (CTD). In recent years, a lot of progress has been made in the diagnosis, treatment and evaluation of PAH. Chinese Rheumatology Association formulated this recommendation on the basis of current experience and guidelines, in order to promote early screening, early diagnosis and early intervention of CTD-PAH, as well as patient follow-up and management, to improve the prognosis of CTD-PAH patients.

Erythrocytes from patients with ST-elevation myocardial infarction induce cardioprotection via the purinergic P2Y13 receptor and nitric oxide signalling

Background

Red blood cells (RBC) are suggested to act as important mediators in the regulation of cardiovascular function by exporting nitric oxide (NO) bioactivity and ATP under hypoxic/ischemic conditions. In addition, RBCs are known to protect from ischemia-reperfusion injury via the export of NO bioactivity in experimental settings. However, it remains unknown if such beneficial effects of RBCs are protective in patients with acute myocardial infarction.

Purpose

To investigate whether RBCs from patients with ST-elevation myocardial infarction (STEMI) protect against myocardial ischemia-reperfusion injury and whether such effect involves activation of purinergic and NO signalling in the RBCs.

Methods

RBCs were collected from patients with STEMI undergoing primary percutaneous coronary intervention and age- and gender-matched healthy controls. The RBCs were administered into the coronary circulation of isolated Langendorff-perfused rat hearts at the onset of global ischemia for 25 min followed by reperfusion of 60 min. Recovery of left ventricular developed pressure (LVDP) during reperfusion and infarct size were determined. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996). The present study was performed following The Code of Ethics of the World Medical Association outlined in the Declaration of Helsinki of 1975 and revised in 1983 for experiments that involve human subjects.

Results

Administration of RBCs from STEMI patients improved recovery of LVDP and reduced infarct size in hearts subjected to ischemia-reperfusion in comparison with RBCs from healthy controls (Figure 1A, B). Pre-incubation of the RBCs with the NO synthase (NOS) inhibitor L-NAME (Figure 1C, D) and the inhibitor of the NO receptor soluble guanylyl cyclase (sGC) ODQ abolished the cardioprotective effect of RBCs from STEMI patients. The cardioprotective effect was also attenuated by inhibition of cardiac cGMP-dependent protein kinase (PKG). Further, the purinergic P2Y13 receptor antagonist MRS2211 (Figure 1E, F), but not the P1 receptor antagonist 8PT applied to RBCs, attenuated the cardioprotection induced by RBCs from STEMI patients. Moreover, administration of RBCs from healthy subjects pre-incubated with a cell permeable ATP analogue improved post-ischemic recovery of LVDP and reduced infarct size. This cardioprotective effect was abolished by co-incubation of the RBCs with ODQ (Figure 2) and MRS2211.

Conclusion

Our findings demonstrate a novel function of RBCs in patients with STEMI that provides protection against myocardial ischemia-reperfusion injury via the activation of P2Y13 receptor and the NO-sGC pathway in RBCs and cardiac PKG.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation; Swedish Research Council

Red blood cells induce endothelial dysfunction in patients with ST-elevation myocardial infarction and elevated C-reactive protein

Background

The important role of inflammation in atherosclerotic plaque progression and instability leading to myocardial infarction has been widely demonstrated. C-reactive protein (CRP) has been shown to be of predictive value in atherosclerotic cardiovascular disease. The red blood cell (RBC) is an important regulator of cardiovascular function through nitric oxide bioactivity and oxidative stress in ischemic heart disease. Also, arginase-1 has been shown to greatly influence nitric oxide bioactivity in RBCs and to cause endothelial dysfunction. However, the mechanisms by which RBCs regulate vascular function in patients with myocardial infarction and its relation to inflammation and arginase-1 remain unknown.

Objective

The study aimed to investigate the effect of RBCs on endothelial function in patients with ST-elevation myocardial infarction (STEMI) and its possible association with systemic inflammation and arginase-1.

Material and methods

Blood samples were collected from patients with STEMI within 36 h after admission and from age-matched healthy controls. RBCs were incubated with isolated rat aortic segments for 18 h after which the aortas were assessed for endothelium-dependent and endothelium-independent relaxations using wire myographs and application of acetylcholine and nitroprusside, respectively. The vascular response was evaluated in relation to the level of inflammation defined as CRP <2 and ≥2 mg/L at admission. The levels of 4-hydroxynonenal (4-HNE; a marker of oxidative stress formed by lipid peroxidation) and the expression of arginase-1 were visualized in rat aortas following incubation with RBCs by immunohistochemistry. All handling and procedures regarding human subjects and sampling were performed according to the Declaration of Helsinki. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996).

Results

RBCs from patients with STEMI and elevated CRP (≥2 mg/L, mean of 9.6 mg/L) induced significant impairment of endothelium-dependent relaxation compared to RBCs from patients with STEMI and low CRP (<2 mg/L, mean of 1.0 mg/L) and to the healthy controls (Fig. 1). Endothelium-independent relaxations did not differ between the groups. Immunohistochemical staining of the aorta revealed that incubation with RBCs from patients with STEMI and high CRP increased the expression of 4-HNE and arginase-1 compared to incubation of RBCs from healthy controls and patients with STEMI and low CRP (Fig. 2).

Conclusion

RBCs from patients with STEMI and elevated CRP induce endothelial dysfunction and increase the expression of 4-HNE and arginase-1, indicating that inflammation is involved in the mechanism by which RBCs induce endothelial dysfunction in STEMI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung foundation

Overexpression of miR-210 ameliorates endothelial dysfunction in type 2 diabetic mice

Background

MicroRNA (miR)-210 plays a protective role in many cardiometabolic diseases, and its levels are reduced in whole blood, erythrocytes, and plasma in type 2 diabetes mellitus (T2DM). Our recent study demonstrated that miR-210 is downregulated in carotid artery plaques from patients with T2DM compared to non-diabetic patients. However, the functional role of miR-210 in endothelial dysfunction is not fully understood.

Purpose

This study aimed to investigate the potential therapeutic value of miR-210 overexpression against T2DM-associated endothelial dysfunction.

Methods

miR-210 transgenic mice (TG) at age of 8 weeks were subjected to Western Diet (WD) for 12 weeks. During the last 10 days of the diet regime, doxycycline or vehicle dissolved in drinking water was given to switch on miR-210 (miR-210/on) expression or keep it off (miR-210/off), respectively. Age-matched wild-type (WT) control mice received normal chow through the same period. Additionally, WT and T2DM db/db mice at age of 15–20 weeks received tail vein injections of miR-210 mimic or miR-210 scramble oligonucleotides. All animals were euthanized at the end of the treatment or 72h after the i.v. injections for determination of endothelial function by acetylcholine-induced endothelium-dependent relaxation (EDR) of isolated aortic segments from all groups of mice using wire myographs. The expression of protein tyrosine phosphatase 1B (PTP1B; a miR-210 target protein) and the levels of 4-hydroxynonenal (4-HNE; an oxidative stress marker) were measured in aortic segments by immunohistochemistry. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996).

Results

EDR in aortic segments from miR-210/off TG mice fed WD and T2DM db/db mice injected with miR-210 scramble was significantly impaired compared to vessels from WT controls fed with regular chow (Fig. 1A, B). Of note, EDR was markedly improved or even restored in aortae from miR-210/on TG mice treated with WD and T2DM db/db mice injected with miR-210 mimic (Fig. 1A, B). Furthermore, the expression of PTP1B and the levels of 4-HNE, which is formed by lipid peroxidation, were significantly elevated in the aortae from miR-210/off TG mice treated with WD when compared to WT controls (Fig. 2A–D). The expression was attenuated in aortae of miR-210/on TG mice treated with WD compared to miR-210/off TG mice (Fig. 2A–D). There was a significant increase in the expression of PTP1B and a trend to increased 4-HNE levels in aortae of db/db mice injected with miR-210 scramble vs. control mice (Fig. 2E–H). A significant reduction in PTP1B but not 4-HNE was observed in db/db mice injected with miR-210 mimic (Fig. 2E–H).

Conclusion

Genetic and pharmacological overexpression of miR-210 ameliorates endothelial dysfunction in mice fed with WD and db/db mice. Increasing miR-210 levels may become a potential treatment strategy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation

[Mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 regimen in the treatment of pediatric Burkitt lymphoma]

Objective: To analyze the clinical characteristics of children with Burkitt lymphoma (BL) and to summarize the mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen. Methods: Clinical features of 436 BL patients who were ≤18 years old and treated with the CNCL-B-NHL-2017 regimen from May 2017 to April 2021 were analyzed retrospectively. Clinical characteristics of patients at disease onset were analyzed and the therapeutic effects of patients with different clinical stages and risk groups were compared. Survival analysis was performed by Kaplan-Meier method, and Cox regression was used to identify the prognostic factors. Results: Among 436 patients, there were 368 (84.4%) males and 68 (15.6%) females, the age of disease onset was 6.0 (4.0, 9.0) years old. According to the St. Jude staging system, there were 4 patients (0.9%) with stage Ⅰ, 30 patients (6.9%) with stage Ⅱ, 217 patients (49.8%) with stage Ⅲ, and 185 patients (42.4%) with stage Ⅳ. All patients were stratified into following risk groups: group A (n=1, 0.2%), group B1 (n=46, 10.6%), group B2 (n=19, 4.4%), group C1 (n=285, 65.4%), group C2 (n=85, 19.5%). Sixty-three patients (14.4%) were treated with chemotherapy only and 373 patients (85.6%) were treated with chemotherapy combined with rituximab. Twenty-one patients (4.8%) suffered from progressive disease, 3 patients (0.7%) relapsed, and 13 patients (3.0%) died of treatment-related complications. The follow-up time of all patients was 24.0 (13.0, 35.0) months, the 2-year event free survival (EFS) rate of all patients was (90.9±1.4) %. The 2-year EFS rates of group A, B1, B2, C1 and C2 were 100.0%, 100.0%, (94.7±5.1) %, (90.7±1.7) % and (85.9±4.0) %, respectively. The 2-year EFS rates was higher in group A, B1, and B2 than those in group C1 (χ²=4.16, P=0.041) and group C2 (χ²=7.21, P=0.007). The 2-year EFS rates of the patients treated with chemotherapy alone and those treated with chemotherapy combined with rituximab were (79.3±5.1)% and (92.9±1.4)% (χ²=14.23, P<0.001) respectively. Multivariate analysis showed that stage Ⅳ (including leukemia stage), serum lactate dehydrogenase (LDH)>4-fold normal value, and with residual tumor in the mid-term evaluation were risk factors for poor prognosis (HR=1.38,1.23,8.52,95%CI 1.05-1.82,1.05-1.43,3.96-18.30). Conclusions: The CNCL-B-NHL-2017 regimen show significant effect in the treatment of pediatric BL. The combination of rituximab improve the efficacy further.

Comparative analysis of R2R3-MYB transcription factors in the flower of Iris laevigata identifies a novel gene regulating tobacco cold tolerance

Breeding for flower cold resistance is a priority for flower breeding research in northern China. The identification of cold resistance genes will not only provide genetic resources for cold resistance breeding, but also form a basis for the study of plant cold resistance mechanisms. Based on the flower transcriptome of Iris laevigata, 20 R2R3-MYBs were identified and comprehensive analysis, including conservative domain, phylogenetic analyses and functional distribution, were performed for R2R3-MYBs. Expression patterns of the abiotic stress genes under cold stress were detected, the upregulated gene was genetically transformed into tobacco, and the related physiological indicators of the transgenic tobacco were measured. A novel cold resistance gene, IlMYB306, was obtained. qRT-PCR indicated that IlMYB306 was dramatically induced by cold stress and was significantly upregulated in roots. The free proline content, MDA, SOD and POD activity of the transgenic tobacco improved after cold stress, and the chlorophyll content decreased slowly. In addition, overexpression of IlMYB306 improved cold resistance of the seeds. SEM results showed leaves of transgenic tobacco had obvious folds, more grooves and bulges on the lower leaf surface. Overall, we report a novel cold resistance R2R3-MYB gene, IlMYB306, in the flower of I. laevigata, which could improve tobacco cold stress tolerance by thickening the waxy layer, increasing antioxidant activity and the content of proline.

Mussel-Inspired Hydrogels for Fluoride Delivery and Caries Prevention

Fluoride agents hold promise for the repair and prevention of caries lesions, but their interaction with enamel is often hampered and diminished because of the dynamic wet environment in the oral cavity, which affects the efficacy of fluoride delivery and limits treatment success. We herein developed a mussel-inspired wet adhesive fluoride system (denoted TS@NaF) fabricated by the self-assembly of tannic acid (TA), silk fibroin (SF), and sodium fluoride (NaF). TS@NaF demonstrated remarkable biological stability and biocompatibility, showed reliable wet adhesion, released fluoride ions (F−) topically, and induced significant deposition of calcium fluoride (CaF2) onto enamel in vitro. Furthermore, TS@NaF provided an anticaries effect in vitro and induced a detectable increase in enamel mineral density. Advanced fluoride-releasing bioadhesives are therefore promising candidates for caries prevention and highlight the great potential of mussel-inspired dental materials in clinical applications.

[Transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin]

Objective: To understand the transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin and provide evidence for COVID-19 prevention and control. Methods: Field epidemiological method was used to investigate the epidemiological characteristics of COVID-19 cases, and descriptive analysis was used to describe the epidemiological information. Results: A total of 430 cases were reported in this epidemic in Tianjin, in which 409 cases were included in this study. Among these cases, 70.90% (290/409) occurred in families. The family secondary attack rate was 33.64% The family secondary attack rate in age group 12-17 years (13.79%) was significantly lower than that in age group 18-49 years (36.48%), the OR was 0.378 (95%CI: 0.170-0.840). The logistic regression analysis showed that compared with centralized quarantine, the OR of the index cases found in closed-off/controlled areas and in home quarantine were 2.951 (95%CI:1.322-6.586) and 2.287 (95%CI:1.164-4.495), respectively, compared with the cases without sore throat, the OR of the index cases with sore throat was 3.003 (95%CI: 1.576-5.720), and compared with cases in families without completed COVID-19 vaccinations in all members, the OR of the cases in families with completed COVID-19 vaccinations in all members was 0.268 (95%CI: 0.132-0.552). Conclusions: The risk of household transmission of infection with Omicron variant was high. Detecting the index case in closed-off/controlled areas or in home quarantine and sore throat in index cases were the risk factors of the household transmission, completed COVID-19 vaccination was the protective factor.

Characterization of rhodanine derivatives as potential disease-modifying drugs for experimental mouse osteoarthritis

OBJECTIVE

This study was performed to characterize selected rhodanine derivatives as potential preclinical disease-modifying drugs for experimental osteoarthritis (OA) in mice.

METHODS

Three rhodanine derivatives, designated rhodanine (R)-501, R-502, and R-503, were selected as candidate OA disease-modifying drugs. Their effects were evaluated by intra-articular (IA) injection in OA mouse models induced by DMM (destabilization of the medial meniscus) or adenoviral overexpression in joint tissues of hypoxia-inducible factor (HIF)-2α or zinc importer ZIP8. The regulatory mechanisms impacted by the rhodanine derivatives were examined in primary-culture chondrocytes and fibroblast-like synoviocytes (FLS).

RESULTS

All three rhodanine derivatives inhibited OA development caused by DMM or overexpression of HIF-2α or ZIP8. Compared to vehicle-treated group, for example, IA injection of R-501 in DMM-operated mice reduced median OARSI grade from 3.78 (IQR 3.00-5.00) to 1.89 (IQR 0.94-2.00, P = 0.0001). R-502 and R-503 also reduced from 3.67 (IQR 2.11-4.56) to 2.00 (IQR 1.00-2.00, P = 0.0030) and 2.00 (IQR 1.83-2.67, P = 0.0378), respectively. Mechanistically, the rhodanine derivatives inhibited the nuclear localization and transcriptional activity of HIF-2α in chondrocytes and FLS. They did not bind to Zn²⁺ or modulate Zn²⁺ homeostasis in chondrocytes or FLS; instead, they inhibited the nuclear localization and transcriptional activity of the Zn²⁺-dependent transcription factor, MTF1. HIF-2α, ZIP8, and interleukin-1β could upregulate matrix-degrading enzymes in chondrocytes and FLS, and the rhodanine derivatives inhibited these effects.

CONCLUSION

IA administration of rhodanine derivatives significantly reduced OA pathogenesis in various mouse models, demonstrating that these derivatives have disease-modifying therapeutic potential against OA pathogenesis.

Research Note: Developmental changes of glucose metabolism are associated with insulin signaling in goose embryo

This study aimed to investigate whether the developmental changes in glucose metabolism were associated with insulin signaling in the middle and later stages of goose embryos. Serum and liver were sampled on embryonic day 19, 22, 25, 28, and day of hatchment, with 30 eggs at each sampling time point, and 6 replicates of 5 embryos. The embryonic growth traits, serum glucose, hormone levels, and the hepatic mRNA expressions of target genes related to glucose metabolism and insulin signaling were measured at each time point. Relative body weight, relative liver weight, and relative body length decreased linearly and quadratically from embryonic day 19 to day of hatchment, while relative yolk weight decreased linearly from embryonic day 19 to day of hatchment. Serum glucose, insulin, and free triiodothyronine levels increased linearly with increasing incubation time, while no differences were observed in serum glucagon and free thyroxine levels. The hepatic mRNA expression related to glucose catabolism (hexokinase, phosphofructokinase, and pyruvate kinase) and insulin signaling (insulin receptor, insulin receptor substrate protein, Src homology collagen protein, extracellular signal-regulated kinase, and ribosomal protein S6 kinase, 70 ku) increased quadratically from embryonic day 19 to day of hatchment. The expression of citrate synthase and isocitrate dehydrogenase mRNA decreased linearly and quadratically respectively from embryonic day 19 to day of hatchment. Serum glucose levels were positively related to serum insulin (r = 1.00) and free triiodothyronine (r = 0.90) levels, as well as the hepatic mRNA expression of insulin receptor (r = 1.00), insulin receptor substrate protein (r = 0.64), extracellular signal-regulated kinase (r = 0.81), and ribosomal protein S6 kinase, 70 ku (r = 0.81) related to insulin signaling. In conclusion, glucose catabolism was enhanced and had positive correlations with the insulin signaling in the middle and later stages of geese embryogenesis.

Computer-aided directed evolution ofl-threonine aldolase for asymmetric biocatalytic synthesis of a chloramphenicol intermediate

l-Threonine aldolases (LTAs) employing pyridoxal phosphate (PLP) as cofactor can convert low-cost achiral substrates glycine and aldehyde directly into valuable β-hydroxy-α-amino acids such as (2R,3S)-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid ((R,S)-AHNPA), which is utilized broadly as crucial chiral intermediates for bioactive compounds. However, LTAs' stereospecificity towards the β carbon is rather moderate and their activity and stability at high substrate load is low, which limits their industrial application. Here, computer-aided directed evolution was applied to improve overall activity, selectivity and stability under desired process conditions of a l-threonine aldolase in the asymmetric synthesis of (R,S)-AHNPA. Selectivity and stability determining regions were computationally identified for structure-guided directed evolution of LTA-variants under efficient biocatalytic process conditions using 40% ethanol as cosolvent. We applied molecular modeling to rationalize selectivity improvement and design focused libraries targeting the substrate binding pocket, and we also used MD simulations in nonaqueous process environment as an effective and promising method to predict potential unstable loop regions near the tetramer interface which are hot-spots for cosolvent resistance. An excellent LTA variant EM-ALDO031 with 18 mutations was obtained, which showed ∼ 30-fold stability improvement in 40% ethanol and diastereoselectivity (de) raised from 31.5% to 85% through a three-phase evolution campaign. Our fast and efficient data-driven methodology utilizing a combination of experimental and computational tools enabled us to evolve an aldolase variant to achieve the target of 90% conversion at up to 150 g/L substrate load in 40% ethanol, enabling the biocatalytic production of β-hydroxy-α-amino acids from cheap achiral precursors at multi-ton scale.

Efficacy and safety of intracoronary pro-urokinase injection during percutaneous coronary intervention in treating ST elevation myocardial infarction patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Intracoronary injection of pro-urokinase (Pro-UK) during percutaneous coronary intervention (PCI) seems to be a promising treatment in improving myocardial perfusion. In this systematic review and meta-analysis, we aimed at investigating the efficacy and safety of intracoronary Pro-UK injection during PCI in ST elevation myocardial infarction (STEMI) patients.

MATERIALS AND METHODS

A comprehensive literature searched on PubMed, Embase, Cochrane, Ovid-MEDLINE, Ovid-Embase, Ovid-Cochrane Databases and ClinicalTrials.gov from inception until June 1, 2022, in English only. The primary outcome was myocardial perfusion, including thrombolysis in myocardial infarction (TIMI) grades, corrected TIMI frame count (CTFC), TIMI myocardial perfusion grades (TMPG). The secondary outcomes were ST-segment resolution (STR), major adverse cardiovascular events (MACE), myocardial marker, cardiac function and hemorrhagic complications.

RESULTS

We identified 5 studies (all RCTs) involving 761 participants. Under PCI procedure, compared with placebo, intracoronary Pro-UK injection may improve myocardial perfusion, including increasing the TIMI grades [odd ratio (OR) 0.46; 95% confidence interval (CI) 0.28-0.75; p = 0.002; I2 = 0%] , CTFC (OR -3.47; 95% CI [-5.60, -1.33]; p = 0.001; I2 = 0%) and TMPG (OR 0.17; 95% CI [0.06-0.44]; p = 0.0003; I2 = 0%), increase the rate of STR (OR 2.25; 95% CI [1.56-3.26]; p < 0.0001; I2 = 0%), reduce the incidence of MACE (OR 0.51; 95% CI [0.33-0.81]; p = 0.004; I2 = 0%) and reduce myocardial infarct size (CK, standardized mean difference [SMD] -0.45; 95% [CI] [-0.62, -0.28]; p < 0.00001; I2 = 10%. CK-MB, [SMD] -0.43; 95% CI [-0.68, -0.18]; p = 0.0007; I2 = 60%. cTnI, [SMD] -0.31; 95% CI [-0.46, -0.17]; p < 0.0001; I2 = 0%). Moreover, the treatment may improve the cardiac functions (LVFE, pooled mean difference [MD] 1.23; 95% CI [0.66-1.79]; p < 0.0001; I2 = 24%. LVEDd, pooled MD -0.13; 95% CI [-0.17, -0.09]; p < 0.00001; I2 = 0%). But there is no statistically significant difference between the Pro-UK group and placebo in the occurrence of hemorrhagic complications (OR 1.19; 95% CI [0.75-1.87]; p = 0.46; I2 = 0%).

CONCLUSIONS

Intracoronary Pro-UK injection during PCI in STEMI patients is an effective and safe treatment to perform. The treatment may improve myocardial perfusion and rate of STR, as well as decreasing the incidence of MACE and myocardial infarct size. Importantly, the treatment may improve the cardiac functions and life quality. In the future, more multi-centered and massive sample studies are required.

[Preliminary evaluation on the efficacy of emergency transcatheter aortic valve replacement: a multicenter study]

Objectives: To explore the efficacy and safety of emergency transcatheter aortic valve replacement (TAVR). Methods: Data of patients who underwent emergency TAVR in eight centers, namely Fuwai Hospital, Wuhan Asia Heart Hospital, Xijing Hospital, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology, Guangdong Provincial People's Hospital, Zhongshan Hospital Affiliated to Fudan University, the First Affiliated Hospital of Zhengzhou University, the Second Xiangya Hospital of Central South University, between May 2017 and December 2020 were retrospectively analyzed. The use of mechanical circulatory support system (MCS) and the results of laboratory tests (N-terminal B-type natriuretic peptide (NT-proBNP)) and echocardiography (mean aortic valve cross valve pressure difference and left ventricular ejection fraction) before and after operation were collected. The primary endpoint was all-cause death, and the secondary endpoints were stroke, major bleeding, major vascular complications, myocardial infarction, permanent pacemaker implantation, and acute renal injury. Device success was caculated, which refered to absence of procedural mortality and correct positioning of a single prosthetic heart valve into the proper anatomical location and intended performance of the prosthetic heart valve (mean aortic valve gradient<20 mmHg(1 mmHg=0.133 kPa) or peak velocity<3 m/s, with no moderate or severe prosthetic valve regurgitation). Kaplan-Meier survival curve was used to estimate the survival rate of patients during follow-up. Results: This study included 48 patients. The age was (72.5±8.1) years, and 34 patients were males (70.8%). Device success rate was 91.7% (44/48). The mean aortic valve transvalvular pressure was significantly decreased after operation ((12.3±6.4)mmHg vs. (60.2±23.8)mmHg, P<0.000 1). Left ventricular ejection fraction was significantly increased ((41.5±11.7)% vs. (31.0±11.3)%, P<0.000 1). NT-proBNP significantly decreased (3 492.0 (1 638.8, 7 165.5) ng/L vs. 12 418.5 (6 693.8, 35 000.0) ng/L, P<0.000 1). In-hospital all-cause mortality was 8.3% (4/48). During hospitalization, the rate of stroke was 2.1% (1/48), major bleeding was 6.3% (3/48), major vascular complications was 10.4% (5/48), myocardial infarction was 4.2% (2/48), permanent pacemaker implantation was 6.3% (3/48), and the rate of acute renal injury was 12.5% (6/48). MCS was used in 20 patients (41.7%). The median follow-up time was 196 days. During the follow-up, one patient died (due to systemic metastasis of pancreatic cancer), two cases suffered new myocardial infarction and one case received permanent pacemaker implantation. The survival rate of 30 days, 1 year and 2 years after the operation were 91.7% (44/48), 89.6% (43/48), 89.6% (43/48), respectively. Conclusion: Emergency TAVR may be a safe and effective treatment for patients with severe decompensated aortic valve stenosis.

[Gastric cancer-derived mesenchymal stem cells regulate the M2 polarization of macrophages within gastric cancer microenvironment via JAK2/STAT3 signaling pathway]

Objective: To investigate the role and mechanism of tumor-derived mesenchymal stem cells in regulating the M2 polarization of macrophages within gastric cancer microenvironment. Methods: Gastric cancer tissues and the adjacent non-cancerous tissues were collected from patients underwent gastric cancer resection in the First People's Hospital of Lianyungang during 2018. In our study, THP-1-differentiated macrophages were co-cultured with gastric cancer-derived mesenchymal stem cells (GC-MSCs). Then, the M2 subtype-related gene, the markers expressed on cell surface and the cytokine profile were analyzed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), flow cytometry and Luminex liquid chip, respectively. The key cytokines mediating the inducing effect of GC-MSCs on macrophage polarization into the M2 subtype were detected and screened by Luminex liquid chip, which were further confirmed by the neutralizing antibody test. The expressions of macrophage proteins involved in M2 polarization-related signaling pathways under the different co-culture conditions of GC-MSCs were detected by western blot. Results: In Mac+ GC-MSC-culture medium (CM) group, the expression levels of Ym-1 and Fizz-1 (1.53±0.32 and 13.22±1.05, respectively), which are markers for M2 subtype, were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.60±0.41) was significantly lower than that of Mac group (1.06±0.38, P=0.023). In Mac+ GC-MSC-Transwell (TW) group, the expression levels of Ym-1 and Fizz-1 (1.47±0.09 and 13.16±2.77, respectively) were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.56±0.03) was significantly lower than that of Mac group (1.06±0.38, P=0.026). The ratios of CD163(+) /CD204(+) cells in Mac+ GC-MSC-CM and Mac+ GC-MSC-TW groups (3.80% and 4.40%, respectively) were both remarkably higher than that of Mac group (0.60%, P<0.05). The expression levels of IL-10, IL-6, MCP-1 and VEGF in Mac+ GC-MSC-CM group were (592.60±87.52), (1 346.80±64.70), (11 256.00±29.03) and (1 463.90±66.67) pg/ml, respectively, which were significantly higher than those of Mac group [(41.03±2.59), (17.35±1.79), (5 213.30±523.71) and (267.12±12.06) pg/ml, respectively, P<0.05]. The levels of TNF-α, IP-10, RANTES and MIP-1α were (95.57±9.34), (410.48±40.68), (6 967.30±1.29) and (1 538.70±283.04) pg/ml, which were significantly lower than those of Mac group [(138.01±24.31, (1 298.60±310.50), (14 631.00±4.21) and (6 633.20±1.47) pg/ml, respectively, P<0.05]. The levels of IL-6 and IL-8 in GC-MSCs [(11 185.02±2.82) and (12 718.03±370.17) pg/ml, respectively] were both strikingly higher than those of MSCs from adjacent non-cancerous gastric cancer tissues [(270.71±59.38) and (106.04±32.84) pg/ml, repectively, P<0.05]. The ratios of CD86(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (28.80% and 31.40%, respectively) were both higher than that of Mac+ GC-MSC-CM group (24.70%). Compared to Mac+ GC-MSC-CM group (13.70%), the ratios of CD204(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (9.90% and 8.70%, separately) were reduced. The expression levels of p-JAK2 and p-STAT3, which are proteins of macrophage M2 polarization-related signaling pathway, in Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, respectively) were significantly higher than those of Mac group (0.50±0.01 and 0.82±0.01, respectively, P<0.05). The expression levels of p-JAK2 in Mac+ IL-6-blocked-GC-MSC-CM group (0.47±0.02) were significantly lower those that of Mac+ GC-MSC-CM group (0.86±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-8-blocked-GC-MSC-CM group (0.50±0.01 and 0.85±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-6/IL-8-blocked-GC-MSC-CM group (0.37±0.01 and 0.65±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). Conclusion: GC-MSCs promote the activation of JAK2/STAT3 signaling pathway in macrophages via high secretions of IL-6 and IL-8, which subsequently induce the macrophage polarization into a pro-tumor M2 subtype within gastric cancer microenvironment.

[A prospective randomized controlled study on the effects of compound analgesia in ultra-pulsed fractional carbon dioxide laser treatment of post-burn hypertrophic scars in children]

Objective: To investigate the effects of compound analgesia on ultra-pulsed fractional carbon dioxide laser (UFCL) treatment of post-burn hypertrophic s in children. Methods: A prospective randomized controlled study was conducted. From April 2018 to March 2020, 169 pediatric patients with post-burn hypertrophic s admitted to the First Affiliated Hospital of Air Force Medical University were randomly divided into general anesthesia alone group (39 cases, 19 males and 20 females, aged 35 (21, 48) months), general anesthesia+lidocaine group (41 cases, 23 males and 18 females, aged 42 (22, 68) months), general anesthesia+ibuprofen suppository group (41 cases, 25 males and 16 females, aged 38 (26, 52) months), and three-drug combination group with general anesthesia + lidocaine+ibuprofen suppository (48 cases, 25 males and 23 females, aged 42 (25, 60) months), and the pediatric patients in each group were treated with corresponding analgesic regimens when UFCL was used to treat s, and the pediatric patients were given comprehensive care throughout the treatment process. The pain degree of pediatric patients scar was evaluated by facial expression,legs,activity,cry,and consolability (FLACC) of children's pain behavior scale at 0 (immediately), 1, 2, and 4 h after awakening from the first anesthesia, respectively. At 4 h after awakening from the first anesthesia of postoperative pain assessment, the self-made analgesia satisfaction questionnaire was used to evaluate the satisfaction for the analgesic effect of the pediatric patients or their families, and the satisfaction rate was calculated. Within 2 h after the first operation, the occurrences of adverse reactions of the pediatric patients, such as nausea and vomiting, headache, dizziness, drowsiness, etc, were observed and recorded. Before the first treatment and 1 month after the last treatment, the Vancouver scar scale (VSS) was used to evaluate the pediatric patients scar, and the difference value between the two was calculated. Data were statistically analyzed with least significant difference test, Kruskal-Wallis H test, chi-square test and Fisher's exact probability test. Results: At 0 h after awakening from the first anesthesia, the FLACC scores of pediatric patients in general anesthesia+lidocaine group, general anesthesia+ibuprofen suppository group and three-drug combination group were significantly lower than those in general anesthesia alone group (P<0.01). The FLACC scores of the pediatric patients in anesthesia+ibuprofen suppository group and three-drug combination group were significantly lower than that in general anesthesia+lidocaine group (P<0.01), and the FLACC score of the pediatric patients in three-drug combination group was significantly lower than that in general anesthesia+ibuprofen suppository group (P<0.01). At 1 and 2 h after awakening from the first anesthesia, the FLACC scores of pediatric patients in general anesthesia+ibuprofen suppository group and three-drug combination group were both significantly lower than those in general anesthesia alone group and general anesthesia+lidocaine group (P<0.01), and the FLACC score of the pediatric patients in three-drug combination group was significantly lower than that in general anesthesia+ibuprofen suppository group (P<0.01). At 4 h after awakening from the first anesthesia, the FLACC scores of the pediatric patients in general anesthesia+ibuprofen suppository group and three-drug combination group were significantly lower than those in general anesthesia alone group and general anesthesia+lidocaine group (P<0.01). At 4 h after awakening from the first anesthesia, the satisfactions rate with the analgesic effect in the four groups of pediatric patients or their families were 79.49% (31/39), 85.37% (35/41), 87.80% (36/41), and 97.92% (47/48), respectively. The satisfaction rate of the pediatric patients in three-drug combination group was significantly higher than those in general anesthesia alone group, general anesthesia+lidocaine group, general anesthesia+ibuprofen suppository group. Within 2 h after the first operation, there was no significant difference in the overall comparison of adverse reactions such as nausea and vomiting, headache, dizziness, and drowsiness of pediatric patients among the 4 groups (P>0.05). The VSS scores of pediatric patients before the first treatment, 1 month after the last treatment, and and the difference value between the two in the 4 groups were not significantly different (P>0.05). Conclusions: Three-drug combination for analgesia has a good effect in the treatment of hypertrophic scars after burn in pediatric patients with UFCL. Pediatric patients or their families are highly satisfied with the effect, and the treatment effect and incidence of adverse reactions are similar to other analgesic regimens, so it is recommended to be promoted in clinical practice.

[Construction of IPA decision model for diabetes prevention and control based on economy and importance]

Objective: To determine the priority of diabetes prevention and control measures in the perspective of the economy and importance, and provide theoretical support for guiding relevant departments to implement measures based on actual economic level. Methods: An online survey was conducted on the importance, feasibility and implementation of major chronic disease prevention and control measures in 488 national demonstration areas for comprehensive chronic disease prevention and control. The content of the survey was divided into individual and group levels, with 10 dimensions and 44 measures, to obtain the scores of the economy and importance. IPA model was used to divide the dimension index of diabetes prevention and control into quadrants. The standardized factor load coefficient of the second-order confirmatory factor analysis was used to determine the priority of dimension index in the same quadrant. The priority of prevention and control measures in each dimension was determined by the discriminant parameter of project response theory. Results: The mean scores of economy and importance were 66.50 and 89.94, respectively, and the matrix was divided into four quadrants. The first quadrant was the "highest priority" with high importance and economy, including medical insurance and family doctors, health education, high-risk detection and intervention, patient management and community action. The second quadrant was characterized as high importance but low economy, which was the priority for improvement, including only one dimension of complication screening. The third quadrant was the lowest priority due to low importance and economy, including personal health service evaluation and follow-up, environmental support, diabetes co-infection prevention and glycemic policy. The last quadrant had low importance but high economy, which was the second improvement level. The priority measures in different quadrants were: (1) the highest priority: blood lipid control, occupational site, prevention and control work plan, blood glucose testing, family doctor contract service; (2) the priority improvement: annual neuropathy screening; (3)the lowest priority: universal access to risk scoring, healthy eating, healthy dining innovations and tuberculosis screening. Conclusion: IPA model can be used to construct a decision-making model for diabetes prevention and control and determine the priority of corresponding measures.

[Changes of serum lipid profiles and the correlation analysis in clinic-pathological features of pancreatic cancer patients]

Objective: To examine the characteristics of blood lipid profile and the correlation with clinic-pathological features of pancreatic cancer patients. Methods: The clinical and pathological data of 265 pancreatic cancer patients who received radical surgical treatment at Department of General Surgery,Qilu Hospital,Shandong University from January 2013 to September 2020 were collected and analyzed retrospectively. Among the 265 pancreatic cancer patients,there were 170 males and 95 females,with age of (61.0±9.6)years(range:28 to 86 years). General information,lipid indicators and clinic-pathological information were collected from electronic medical record system,and follow-up information gained by telephone. According to level of serum lipid in pancreatic cancer patients,265 patients were divided into dyslipidemia group(n=115) and normal lipid group(n=150). Pearson χ2,Student's t tests, variance analysis or univariate Logistic regression was used to analyze the correlation between dyslipidemia and clinico-pathological characteristics of pancreatic cancer,respectively. Kaplan-Meier survival curve was used to assessed the influence of dyslipidemia on prognosis of pancreatic cancer patients. Results: In 265 pancreatic cancer patients,115(43.4%)of them had dyslipidemias,and the most common form was increase of triglyceride(TG)(72.2%). In pancreatic cancer with dyslipidemias group,patients with body mass index ≥25 kg/m2 had higher proportion than normal lipid group(36.1%(26/72) vs. 21.2%(21/99),χ²=4.643,P=0.031); The proportion of carcinoma located at head of pancreas(83.5%(96/115) vs. 40.7%(61/150),χ²=49.412,P<0.01), staging of T1/T2(79.1%(91/115) vs. 60.7%(91/150),χ²=10.316,P<0.01) and lymphatic metastasis(36.5%(42/115) vs. 22.7%(34/150),χ²=6.007,P<0.01) were higher. In patients of pancreatic cancer, dyslipidemias were closely associated with tumor location(OR=10.529,P<0.01)and body mass index(OR=3.671,P=0.008). Serum lipid profile results showed that TG,total cholesterol and high-density lipoprotein(HDL) disorders were associated with tumor location(P<0.05). TG disorder had association with body mass index(P<0.05), and HDL disorder had association with tumor stage(P<0.05). Moreover, the result of survival analysis showed that dyslipidemia was not a factor to impact the prognosis of pancreatic cancer patients underwent surgery(P>0.05). Conclusions: In pancreatic cancer patients,TG disorder was the most common type of dyslipidemia. Dyslipidemia has closely association with clinicopathologic features,including tumor location,body mass index,tumor stage. However,dyslipidemia had little effect on prognosis of pancreatic cancer patients.

[Study of the effect of liraglutide on the correlation between NLRP3 inflammasome and non-alcoholic fatty liver disease]

Objective: To observe the effect of liraglutide on the correlation between nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) infl ammasome and nonalcoholic fatty liver disease (NAFLD). Methods: Thirty-nine NAFLD cases (group N) and thirty-nine healthy subjects (group C) were selected from the physical examination center, and their general data were collected to determine the serum levels of NLRP3, IL-1β, and IL-18. The differences and correlations were analyzed between the two sets of indicators. Thirty male SD rats were randomly divided into normal (NC, n=10) and high-fat diet group (HF, n=20). The normal group were fed with normal diet and high-fat diet group were fed with high-fat diet. After 12 weeks of feeding, HF group was randomly divided into HF group (n=10) and liraglutide group (100L, n=10), and were given 0.5 ml/kg sterile isotonic saline and 100 g/kg liraglutide subcutaneously twice a day, respectively. Four weeks later, serum biochemical indicators, liver NLRP3 infl ammasome protein expression, and infl ammatory cytokine conditions were detected in each group. Statistical analysis was performed using t test, oneway analysis of variance (ANOVA) or χ² test. Results: There were no statistically signifi cant differences between N and C group in terms of age, gender, diastolic blood pressure, glycosylated hemoglobin, mean platelet volume, erythrocyte distribution width, serum low-density lipoprotein cholesterol (HDL-Ch), total cholesterol, and total bileacid. Compared with group C, group N had elevated systolic blood pressure, body mass index (BMI), fasting blood glucose, blood creatinine, alkaline phosphatase (ALP), NLRP3, interleukin (IL)-1β, IL-18, TG, blood uric acid, γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and white blood cell counts, while HDL-Ch and total bilirubin were depleted than group C, and the difference was statistically significant (P< 0.05). NLRP3 was positively correlated with systolic blood pressure, BMI, fasting blood glucose, serum creatinine, IL-1β, IL-18, triglycerides, serum uric acid, GGT, ALT, AST, but negatively correlated with total bilirubin and HDL-Ch, and the difference was statistically signifi cant. Compared with NC group, HF group had significantly increased body mass, liver mass, serum biochemical indicators (triglycerides, AST, ALT), liver NLRP3 inflammasome protein expression, and inflammatory cytokines. After treatment with liraglutide, 100L group indicators were signifi cantly decreased when compared to HF group. Conclusion: Compared with healthy subjects, the infl ammation-related indicators, body mass, blood lipids and liver function-related indicators are signifi cantly changed in patients with NAFLD, which is also consistent with the results of rat model study. Liraglutide treatment had improved NAFLD to certain extent in NAFLD rats, so NLRP3 regulation may be one of the mechanisms to improve liver inflammation and steatosis.

Photonic crystal resonators for inverse-designed multi-dimensional optical interconnects

We experimentally demonstrate a 400 Gbit/s optical communication link utilizing wavelength-division multiplexing and mode-division multiplexing for a total of 40 channels. This link utilizes a novel, to the best of our knowledge, 400 GHz frequency comb source based on a chip-scale photonic crystal resonator. Silicon-on-insulator photonic inverse-designed 4 × 4 mode-division multiplexer structures enable a fourfold increase in data capacity. We show less than -10 dBm of optical receiver power for error-free data transmission in 34 out of a total of 40 channels using a PRBS31 pattern.

Polydatin alleviates osteoporosis by enhancing the osteogenic differentiation of osteoblasts

OBJECTIVE: Osteoporosis is a severe degenerative chronic metabolic bone disease associated with high fracture risk. Polydatin (PD), a major bioactive component of Polygonum cuspidatum, has antioxidant and anti-inflammatory effects. This study investigated the anti-osteoporotic activity of PD in ovariectomized (OVX) mice and elucidated its underlying molecular mechanisms. SUBJECTS AND METHODS: An osteoporosis mouse model was established using OVX mice. OVX mice were then administered 10 or 40 mg/kg of PD for 60 days. Micro-CT and three-point bending tests were used to determine the therapeutic activities of PD in OVX mice. H&E staining was used to determine whether PD induced hepatorenal toxicity. In addition, the cellular and molecular mechanisms underlying the functionality of PD were elucidated. RESULTS: Micro-CT results showed that compared to control mice, the bone mass of OVX mice was significantly reduced due to estrogen deficiency; however, PD administration significantly elevated bone mass. Furthermore, PD substantially improved the trabecular microstructure parameters of the femur and enhanced bone strength compared with OVX mice. Hepatorenal toxicity was not observed in liver and kidney samples stained with H&E. PD significantly increased the proliferation of pre-osteoblast MC3T3-E1 cells and upregulated the expression of osteogenic differentiation markers compared to those in controls, as determined by qRT-PCR and western blotting. CONCLUSIONS: PD exerted a significant anti-osteoporotic effect in OVX mice by promoting osteogenesis. PD has great potential as a therapeutic option for osteoporosis.

AB1427 ASSOCIATION BETWEEN HYPERURICEMIA AND OSTEOPOROTIC IN CHINESE ADULTS, A CROSS-SECTIONAL STUDY

Background

Hyperuricemia may have a protective role in diseases characterized by high levels of oxidative stress, such as osteoporosis. Previous studies have shown that hyperuricemia is associated with osteoporotic. However, this association is controversial and even yielded conflicting results.

Objectives

This study investigated the relationship between hyperuricemia and osteoporotic among Chinese adults.

Methods

The data of cross-sectional study was collected at Guangdong Second Provincial General Hospital in Guangzhou City, China between January 2009 and December 2019. Physical examinations and laboratory measurement variables were obtained from the medical check-up system. The multivariate-adjusted logistic regression model was performed to assess the association between hyperuricemia and osteoporotic.

Results

A total of 18917 participants (11334 males and 7579 females) were included in this study, with an average age of 46.23 years (SD: 11.67) at baseline. It included 5881 cases of hyperuricemia and 1587 osteoporotic. After adjusted for the confounding factors in logistic regression analysis, we observed a negative significant association between hyperuricemia and risk of osteoporotic (odds ratio [OR],0.852, 95%CI 0.795–0.967; P <0.05). Further stratified analyses showed a negative significant association with the risk of osteoporotic in women (OR,0.787, 95%CI 0.698–0.853; P <0.05), man (OR,0.897, 95%CI 0.786–0.954; P <0.05) and old adults (OR, 0.808, 95%CI, 0.759-0.894; P <0.05). No significant differences in other groups.

Conclusion

Our study observed participants with hyperuricemia had significantly less osteoporosis. More high-quality research is needed to further support these findings.

References

[1]Zong Q, Hu Y, Zhang Q, Zhang X, Huang J, Wang T. Associations of hyperuricemia, gout, and UA-lowering therapy with the risk of fractures: A meta-analysis of observational studies. Joint Bone Spine. 2019 Jul;86(4):419-427.

[2]Wang Y, Zhou R, Zhong W, Hu C, Lu S, Chai Y. Association of gout with osteoporotic fractures. Int Orthop. 2018 Sep;42(9):2041-2047.

[3]Veronese N, Carraro S, Bano G, Trevisan C, Solmi M, Luchini C, Manzato E,Caccialanza R, Sergi G, Nicetto D, Cereda E. Hyperuricemia protects against low bone mineral density, osteoporosis and fractures: a systematic review and meta-analysis. Eur J Clin Invest. 2016 Nov;46(11):920-930.

[4]Veronese N, Bolzetta F, De Rui M, Maggi S, Noale M, Zambon S, Corti MC, Toffanello ED, Baggio G, Perissinotto E, Crepaldi G, Manzato E, Sergi G. Serum uric acid and incident osteoporotic fractures in old people: The PRO.V.A study. Bone. 2015 Oct;79:183-9.

Figure 1.

Distribution of hyperuricemia and osteoporotic by gender.

Disclosure of Interests

None declared

Review of benefits and adverse effects of the most commonly used local anesthetic adjuvants in peripheral nerve blocks

Recently, peripheral nerve blocks are extensively applied for many patients undergoing surgical or nonsurgical analgesia. However, the effectiveness is limited by the duration of action of local anesthetics. Therefore, the application of adding local anesthetic adjuvants is evolved to prolong the duration of analgesia and decrease the concentration of local anesthetics in peripheral nerve blocks. There are many local anesthetic adjuvants available such as morphine, fentanyl, sufentanil, hydromorphone, and buprenorphine, dexmedetomidine, dexamethasone, midazolam, and magnesium sulfate. Most of them are safe and possess little adverse effects, while none of them is acknowledged by the food and drug administration. Therefore, this review is aimed to delineate benefits and adverse effects for clinical anesthesia.

Hydrogen sulphide regulates the growth of tomato root cells by affecting cell wall biosynthesis under CuO NPs stress

Copper oxide nanoparticles (CuO NPs) show strong nano-toxic effects on organisms. Hydrogen sulphide (H₂ S) plays a pivotal role in plant response to abiotic stress. In this study, we examine the crucial role of the cell wall as regulated by H₂ S in response to CuO NPs stress. The digestion method was employed to determine Cu content using atomic absorption spectrometry. The TraKine pro-tubulin staining kit was used to investigate the microtubule cytoskeleton using confocal laser-scanning microscopy. Cell wall component analysis utilized the ICS-3000 HPLC system. Application of H₂ S reduced growth inhibition caused by CuO NPs. Furthermore, most of the CuO NPs accumulates in roots, indicating a low transfer rate, and H₂ S significantly decreased CuO NPs content in roots, leaves and stems. Subcellular distribution analysis implied most Cu accumulated in root cell walls, and that H₂ S reduced the content of Cu in root cell walls. Cortical microtubules in the plasma membrane, guide cell wall biosynthesis. H₂ S obviously alleviated microtubule cytoskeleton disorders caused by CuO NPs. In addition, the content of cellulose, hemicellulose, pectin and other monosaccharides in root cell walls was reduced by CuO NPs treatment. H₂ S enhanced the monosaccharide and polysaccharide contents compared with that after CuO NPs treatment. In conclusion, H₂ S regulates cell wall development in response to CuO NPs stress by stabilizing microtubules. H₂ S affected Cu distribution and alleviated growth inhibition of tomato seedlings. The research results provide a theoretical basis for further study of nano-toxicity regulation in plants.