Protective Effect of Lemon Peel Extract on Oxidative Stress in H9c2 Rat Heart Cell Injury

Aim

Lemon peel, a traditional Chinese medicine, was tested in this study for its novel application in inhibiting cellular oxidative stress, and the effect of lemon peel extract (LPE) on protecting H9c2 rat heart cells from oxidative stress was investigated.

Methods

The scavenging effects of LPE on 1,1-diphenyl-2-picryhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radicals were measured in extracellular experiments. The 3-(4,5-dimethyl-2-thiazolinyl)-2,5-diphenyl-2-h-tetrazolylammonium bromide (MTT) assay was used to detect the cell survival rate. The cell supernatant and intracellular oxidation-related indicators were detected by a kit, and the mRNA expression in H9c2 cells was detected by quantitative polymerase chain reaction (qPCR). The chemical substances of LPE were analyzed by high-performance liquid chromatography (HPLC).

Results

The results showed that LPE exhibited better DPPH and ABTS free radical scavenging abilities than vitamin C. Compared with the cells in the normal state (control group), the cell survival rate in the model group decreased, and the level of lactate dehydrogenase (LDH) increased, the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) decreased, and the content of malondialdehyde (MDA) increased. Compared with the control group, the expression of Bcl-2-related X protein (Bax), caspase-3, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in the model group was increased, and the expression of B-cell lymphoma-2 (Bcl-2) was reduced. Compared with the model group, LPE treatment improved the cell survival rate, reduced the levels of LDH and MDA, increased the levels of SOD, CAT, and GSH, downregulated the expression of Bax, caspase-3, Nrf2 and HO-1, and upregulated the expression of Bcl-2. The composition analysis showed that LPE contained catechin, rutin, naringin, quercetin, and hesperidin.

Conclusion

The results indicated that LPE could protect H9c2 cells from oxidative stress through five active components. LPE has the potential to be developed into natural medicine or health food for the inhibition of cell oxidative damage.

[CRISPR/Cas9-mediated TEAD1 knockout induces phenotypic modulation of corpus cavernosum smooth muscle cells in diabetic rats with erectile dysfunction]

OBJECTIVE

To construct a corpus cavemosum smooth muscle cell (CCSMCs) line with TEAD1 knockout from diabetic rats with erectile dysfunction (ED) using CRISPR/Cas9 technology and explore the role of TEAD1 in phenotypic modulation of CCSMCs in diabetic rats with ED.

OBJECTIVE

Models of diabetic ED were established in male Sprague-Dawley rats by intraperitoneal injection of streptozotocin. CCSMCs from the rat models were primarily cultured and identified with immunofluorescence assay. Three sgRNAs (sgRNA-1, sgRNA-2 and sgRNA-3) were transfected via lentiviral vectors into 293T cells to prepare the sgRNA-Cas9 lentivirus. CCSMCs from diabetic rats with ED were infected by the lentivirus, and the cellular expression of TEAD1 protein was detected using Western blotting. In CCSMCs infected with the sgRNA-Cas9 lentivirus (CCSMCs-sgRNA-2), or the empty lentiviral vector (CCSMCs-sgRNA-NC) and the blank control cells (CCSMCs-CK), the expressions of cellular phenotypic markers SMMHC, calponin and PCNA at the mRNA and protein levels were detected using real-time fluorescence quantitative RT-PCR (qRT-PCR) and Western blotting, respectively.

OBJECTIVE

The primarily cultured CCSMCs from diabetic rats with ED showed a high α-SMA-positive rate of over 95%. The recombinant lentivirus of TEAD1-sgRNA was successfully packaged, and stable TEAD1-deficient CCSMC lines derived from diabetic rat with ED were obtained. Western blotting confirmed that the protein expression of TEAD1 in TEAD1-sgRNA-2 group was the lowest (P < 0.05), and this cell line was used in subsequent experiment. The results of qRT-PCR and Western blotting showed significantly up-regulated expressions of SMMHC and calponin (all P < 0.05) and down-regulated expression of PCNA (all P < 0.05) at both the mRNA and protein levels in TEAD1-deficient CCSMCs from diabetic rats with ED.

OBJECTIVE

We successfully constructed a stable CCSMCs line with CRISPR/Cas9-mediated TEAD1 knockout from diabetic rats with ED. TEAD1 gene knockout can induce phenotype transformation of the CCSMCs from diabetic rats with ED from the synthetic to the contractile type.

[Correlation analysis between serum ferritin level and liver damage in acute stage of dengue fever]

Objective: To investigate the correlation between serum ferritin (SF) level and liver damage in the acute stage of dengue fever. Methods: A retrospective study was conducted to analyze 171 cases diagnosed with dengue fever as dengue fever group and 130 healthy patients as control group in Hangzhou 3A grade hospital from July to December 2017. Clinical data, SF and liver function related indicators were collected from both groups: alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) to analyze the correlation between liver damage and SF in patients with dengue fever. Results: ALT, AST, and SF levels were significantly higher in the dengue fever group than those in the healthy control group (Z = 11.553, 15.054 and 15.163, P < 0.001). SF levels were higher in the dengue fever combined with liver damage group than those without the liver damage group (z = 6.930, P < 0.001). However, there was no statistically significant differences in age, gender, peak body temperature, and history of liver disease (P > 0.05). In addition, Spearman's correlation analysis showed that SF was positively correlated with ALT, AST, and TBIL (r = 0.464, 0.531 and 0.315, P < 0.001). Among dengue patients with different SF levels, there were significant difference in ALT, AST levels and incidence of liver damage (H = 14.240 and 17.584, χ(2) = 49.547, P < 0.001). Patients with higher SF levels had higher ALT, AST levels and incidence of liver damage. Binary logistic regression analysis showed that hyperferritinemia (SF≥500 ng/ml) was the risk factor for dengue fever combined with liver damage (OR = 8.120, P < 0.001). Furthermore, ROC curve analysis showed that the AUC for SF to judge dengue fever combined liver damage was 0.846 (95% CI: 0.785-0.908), and the sensitivity and specificity when the SF cut-off value was 1 506 ng/ml were 74.8% and 83.3%. Conclusion: There is a certain correlation between the SF level and the degree of liver damage in acute stage of dengue fever patients, and hyperferritinemia is a risk factor for dengue fever combined with liver damage.

Linc-ROR promotes mesenchymal stem cells chondrogenesis and cartilage formation via regulating SOX9 expression

OBJECTIVE

The present study is to characterize the role of long intergenic non-coding RNA, regulator of reprogramming (linc-ROR) in bone marrow mesenchymal stem cell (BMSCs) chondrogenesis, cartilage formation and OA development.

METHODS

Linc-ROR expression pattern in articular cartilage tissue sample from OA patients were studied by real-time PCR. Linc-ROR lentivirus mediated BMSCs were constructed. In vitro micromass cultured BMSCs chondrogenesis or in vivo MeHA hydrogel encapsulated BMSCs cartilage formation activity were studied. Linc-ROR associating miRNAs which repressed SOX9 expression were characterized by luciferase assay, real-time PCR and Western blot. Linc-ROR was co-transfected with miRNAs into BMSCs to study its rescue effect on SOX9 expression and chondrogenesis activity.

RESULTS

Linc-ROR was down-regulated in articular cartilage tissue from OA patients and was positively correlated with the expression level of SOX9 (R² = 0.43). Linc-ROR expression was upregulated during BMSCs chondrogenesis. Linc-ROR ectopic expression significantly promoted in vitro BMSCs chondrogenesis and in vivo cartilage formation activities as revealed by safranin O, alcian blue and COL II staining. The mRNA expression level of chondrogenesis markers including COL II, SOX9 and ACAN were increased, and the hypertrophy markers MMP13 and COL X were decreased upon linc-ROR overexpression in BMSCs. Linc-ROR functioned as a miRNA sponge for miR-138 and miR-145. Both miR-138 and miR-145 suppressed BMSCs chondrogenesis activity and SOX9 expression, while co-expression of linc-ROR displayed a rescuing effect.

CONCLUSIONS

Taken together, linc-ROR modulated BMSCs chondrogenesis differentiation and cartilage formation by acting as a competing endogenous RNA for miR-138 and miR-145 and activating SOX9 expression. Linc-ROR could be considered as a new diagnostic and therapeutic target for OA treatment.

Observation of a Near-Threshold Structure in the K^{+} Recoil-Mass Spectra in e^{+}e^{-}→K^{+}(D_{s}^{-}D^{*0}+D_{s}^{*-}D^{0})

We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7  fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrt[s]=4.681  GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1)  MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0)  MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3  σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.

Predictors of morbidity and mortality in COVID-19

The mortality of COVID-19 patients is increasing in logarithmic fashion and is mostly observed in older age people and patients having history of chronic ailments like chronic obstructive pulmonary disease (COPD), hypertension, diabetes, cardiovascular & cerebrovascular dysfunction, compromised immunity, renal comorbidities, hepatic, obesity problems etc., and recently investigated thrombotic complications. The molecular underpinnings linking the chronic human diseases with COVID-19 related morbidity and mortality are evolving and poorly understood. The aim of the present review is to discuss the mortality and morbidity in COVID-19 in relation to preexisting comorbidities across the globe, upcoming molecular mechanisms associated with expression profile of ACE2 and viral load, evolving pathophysiology of COVID-19 with special reference to thrombotic complication ('Storm of Blood Clots') and related predictive markers. The levels of plasminogen/plasmin in comorbid diseases of COVID-19 have been elaborated in the framework of risk and benefits of fibrinolysis in COVID-19. We have also attempted to discuss the puzzle of prescribing ARBs and ACEI drugs in COVID-19 management which are routinely prescribed for the management of hypertension in COVID-19 patients. A focused discourse on risk of cardiovascular complications and diabetes in concert with COVID-19 pathogenesis has been presented along with dynamics of SARS-CoV-2 induced immune dysfunctions in COVID-19 patients.

Endovascular treatment of visceral aneurysms and pseudoaneurysms

Visceral artery aneurysm (VAA) is a rare and potentially life-threatening condition, defined as true artery aneurysms and pseudoaneurysms of splanchnic circulation and renal artery. This study reports our experience in the diagnosis and endovascular treatment of visceral artery aneurysms (VAAs) over a 10-year period. Between 2008 and 2018, a total of 24 VAAs in 21 patients were diagnosed by clinical symptoms and a combination of imaging techniques, such as Doppler ultrasound, computed tomography angiogram, and catheter angiogram. All patients underwent endovascular treatment to exclude aneurysms. Oral antiplatelet medicine was administered, and imaging examination was performed during follow-up. Technical success was achieved in all 21 patients, and no periprocedural complications occurred. Endovascular coiling alone was employed in 10 aneurysms. Coiling was combined with gelfoam in 2 aneurysms. Coiling was assisted by stent in 4 aneurysms. Covered stents were deployed in 8 aneurysms individually. Clinical symptoms disappeared or highly improved in all patients after treatment. None of the patients showed recurrent symptoms after discharge. However, two cases with new aneurysms after 6 and 8 months, respectively, and one case with in-stent thrombosis after 12 months were reported during follow-up. This study may justify the efficacy of percutaneous endovascular coil embolization and stent deployment. It also provides beneficial experience about how to choose appropriate various endovascular strategies based on both clinical symptoms and aneurysm anatomy condition.

Model-Independent Determination of the Spin of the Ω^{-} and Its Polarization Alignment in ψ(3686)→Ω^{-}Ω[over ¯]^{+}

We present an analysis of the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} (Ω^{-}→K^{-}Λ, Ω[over ¯]^{+}→K^{+}Λ[over ¯], Λ→pπ^{-}, Λ[over ¯]→p[over ¯]π^{+}) based on a dataset of 448×10^{6}  ψ(3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} and the decay parameters of the subsequent decay Ω^{-}→K^{-}Λ (Ω[over ¯]^{+}→K^{+}Λ[over ¯]) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω^{-} is determined to be 3/2 for the first time since its discovery more than 50 years ago.

Characterization of Oxygenated Heterocyclic Compounds and in vitro Antioxidant Activity of Pomelo Essential Oil

Purpose

Citrus essential oils are widely used for aromatherapy and the alternative treatment of chronic diseases. Beyond the aroma substances, they are known to contain bioactive nonvolatile components; however, little knowledge has been gained about nonvolatiles in the essential oil of pomelo (Citrus grandis Osbeck), the largest citrus fruit. The purpose of this study was to analyze the nonvolatile oxygenated heterocyclic compounds (OHCs) of pomelo essential oils and evaluate their in vitro antioxidant activities for further development.

Methods

Cold-pressed essential oil (CPEO) and distilled essential oil (DEO) were obtained from the peel of the Liangping pomelo cultivar. High-performance liquid chromatography (HPLC) coupled with a photodiode array and fluorescence detection method was developed to identify and quantify the OHCs of the two essential oils. Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide (PTIO) radical scavenging assays were used to determine the antioxidative capabilities.

Results

Thirteen OHCs were identified in CPEO. Coumarins such as meranzin (2.0 mmol L⁻¹) and furanocoumarins such as isoimperatorin (1.3 mmol L⁻¹) composed the majority of nonvolatiles in CPEO. These OHCs were characterized by high proportion (58%) of side chain epoxides. Five OHCs, namely, auraptenol, 6ʹ,7ʹ-dihydroxybergamottin (6ʹ,7ʹ-DHB), imperatorin, isoimperatorin and 8-geranyloxypsoralen were first identified in pomelo CPEO. Eight OHCs were detected at trace amounts in pomelo DEO. Antioxidant assays showed that CPEO was multiple times more potent than DEO regarding the total reducing power and radical scavenging capacity. Clearance of PTIO, a stable reactive oxygen species, followed slow kinetics.

Conclusion

Coumarins and furanocoumarins, two families of OHCs, constituted most of the nonvolatile components in CPEO. The nonvolatiles contributed significantly to the in vitro antioxidant activity of CPEO. Pomelo CPEO showed good prospects as a potential long-lasting natural antioxidant.

Microsatellite markers reveal polymorphisms at the 3′ untranslated region of the SLC11A1 gene in Zhongdian Yellow cattle (Bos taurus)

Solute carrier family 11-member A1 (SLC11A1) gene encodes natural macrophage resistance-associated protein which regulates activity of macrophages against intracellular pathogens. The objective of this study was to study the polymorphism in the microsatellites present at 3′ untranslated region (UTR) of the SLC11A1 gene in 113 Zhongdian Yellow cattle (Bos taurus). Using DNA bi-directional sequencing, we detected seven alleles (GT10–16) for the first microsatellite (MS1), five alleles (GT12–16) for MS2, and four alleles (GT4–7) for MS3. MS3 is studied for the first time and revealed four novel variants (alleles GT4–7). Alleles GT12 (45.1%), GT13 (59.3%), and GT5 (85.4%) were the most frequent alleles at MS1, MS2, and MS3, respectively, Genotypes G12/12, G13/13, and G5/5 had the highest frequency 0.239, 0.540, and 0.743 at MS1, MS2, and MS3, respectively. Haplotypic data revealed that GT12/GT13 was the most frequent haplotype observed followed by GT12/14 haplotype. Three nucleotide variations were observed in MS1 and MS2. Comparative analysis of GT12/GT12 and GT13/GT13 genotype with other bovine genotypes showed significant difference (P > 0.05). Our results suggest that the homozygous genotypes GT12/GT12 and GT13/GT13 in Zhongdian Yellow cattle might be related to disease resistance. The findings reported in this study would be helpful in cattle breeding programs.

Mode of action and structural modelling of the interaction of formononetin with suilysin

AIMS

Suilysin is a critical pore-forming virulence factor of Streptococcus suis that has been demonstrated to substantially contribute to its pathogenicity. We have demonstrated that formononetin alleviates S. suis infection both in vivo and in vitro by targeting suilysin. However, the molecular mechanism of the effect is unclear. Our aim was to determine the molecular mechanism of the effect of formononetin on suilysin.

METHODS AND RESULTS

The mechanism of interaction between formononetin and suilysin was investigated by molecular modelling. The results indicated that formononetin was bound at the junction of domain two and domain four of suilysin. The binding free energy values indicated that the A415, Y412, E414, N413, T61, T62 and G416 residues are critical for this binding, this observation was confirmed by the changes in the flexibility of these residues and the distances between these residues and formononetin. The inhibitory effect of formononetin on the pore-forming activity of suilysin, binding constant and binding free energy were significantly decreased by site-specific mutagenesis of Y412 and N413. Finally, we analysed the spatial configuration of suilysin before and after formononetin binding, the results indicated that the binding changed the conformation of suilysin, especially the angle between domain two and domain four, resulting in the disruption of cholesterol binding to suilysin and in the loss of pore-forming activity.

CONCLUSIONS

Formononetin is located at the junction of domain two and domain four of suilysin, and Y412 and N413 play critical roles in the binding. Formononetin binding changes the angle between domain two and domain four of suilysin, resulting in the loss of the pore-inducing activity of suilysin.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work will promote the application of formononetin to combat S. suis infections and may contribute to the development of new inhibitors or modification of existing inhibitors.

[Fuxinfang improves hypoxia-induced injury of human aortic endothelial cells by regulating c-Fos-NR4A1-p38 pathway]

OBJECTIVE

To explore the molecular mechanism of Fuxinfang for improving injury of human aortic endothelial progenitor cells (HAECs).

OBJECTIVE

Serum samples were collected from male SD rats treated with Fuxinfang (n=8) or saline (n= 5). HAECs cultured in normoxia or hypoxic condition (2% O₂) were treated with serum from normal rats or with diluted serum (1% and 10%) from rats treated with Fuxinfang. The differentially expressed genes (DEGs) between Fuxinfang-treated and control cells were detected using high-throughput sequencing to screen the target DEGs that participated in arterial endothelial cell injury and underwent changes in response to both hypoxia and Fuxinfang treatment. AmiGo and String databases were used to infer the interactions among the target genes, and the expressions of the genes were analyzed in HAECs with different treatments using enzyme-linked immunosorbent assay (ELISA) and Western blotting.

OBJECTIVE

HAECs cultured in hypoxia did not show obvious changes in cell morphology or expressions of hypoxia-related factors in response to treatment with 1% or 10% serum from Fuxinfang-treated rats. The results of high-throughput sequencing showed a total of 7134 DEGs (4205 up-regulated and 2929 down-regulated genes) in HAECs in hypoxia model group and 762 DEGs (305 upregulated and 457 down-regulated genes) in Fuxinfang-treated HAECs. Analysis of AmiGo and String databases and the constructed protein-protein interaction network identified c-Fos, NR4A1, and p38MAPK as the target genes. The results of ELISA and Western blotting showed that the expressions of c-Fos, NR4A1, p38MAPK and pp38MAPK increased significantly in cells with hypoxic exposure (P < 0.05); treatment with the serum containing Fuxinfang significantly reduced the expression levels of c-Fos, NR4A1 and p-p38MAPK in hypoxic HAECs in a concentration-dependent manner (P < 0.05).

OBJECTIVE

The serum from Fuxinfang-treated rats can concentration-dependently inhibit the expressions of the DEGs occurring in hypoxia. Fuxinfang improves hypoxic injuries of HAECs possibly by down-regulating the expression of c-Fos to inhibit NR4A1 expression and suppressing hypoxia-induced p38 phosphorylation.

Totally endoscopic sublay (TES) repair for lateral abdominal wall hernias: technique and first results

BACKGROUND

The optimal surgical treatment for lateral hernias of the abdominal wall remains unclear. The presented prospective study assesses for the first time in detail the clinical value of a totally endoscopic sublay (TES) technique for the repair of these hernias.

METHODS

Twenty-four consecutive patients with a lateral abdominal wall hernia underwent TES repair. This technique is naturally combined with a transversus abdominis release maneuver to create a sufficient retromuscular/preperitoneal space that can accommodate, if necessary, a giant prosthetic mesh.

RESULTS

The operations were successful in all but one patient who required open conversion because of dense intestinal adhesion. The mean defect width was 6.7 ± 3.9 cm. The mean defect area was 78.0 ± 102.4 cm² (range 4-500 cm²). The mean mesh size used was 330.2 ± 165.4 cm² (range 108-900 cm²). The mean operative time was 170.2 ± 73.8 min (range, 60-360 min). The mean visual analog scale score for pain at rest on the first day was 2.5 (range 1-4). The average postoperative stay was 3.4 days (range 2-7 days). No serious complications (Dindo-Clavien Grade 2-4) were seen within a mean follow-up period of 13.3 months.

CONCLUSIONS

A totally endoscopic technique (TES) for the treatment of lateral hernias is described. The technique revealed to be reliable, safe and cost-effective. The first results are promising, but larger studies with longer follow-up periods are recommended to determine the real clinical value.

Circ-DONSON promotes malignant progression of glioma through modulating FOXO3

OBJECTIVE

The aim of this study was to investigate the expression level of circ-DONSON in glioma and to explore its effect on glioma metastasis and the underlying mechanism.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine circ-DONSON expression in 40 paired glioma tumor tissues and adjacent tissues. Meanwhile, the relation between circ-DONSON level and clinical parameters of glioma and the prognosis of patients was analyzed. The expression of circ-DONSON in glioma cell lines was analyzed by qRT-PCR as well. In addition, circs-DONSON silencing model was constructed in glioma cell lines. Cell counting kit-8 (CCK-8), cell scratch, and transwell migration assays were performed to investigate the effect of circ-DONSON on biological functions of glioma cells. Finally, the interplay between FOXO3 and circ-DONSON was explored.

RESULTS

QRT-PCR results revealed that the expression level of circ-DONSON in glioma tumor tissues was remarkably higher than that of adjacent tissues, and the difference was statistically significant (p<0.05). Compared with patients with low expression of circ-DONSON, significantly higher prevalence of lymph node or distant metastasis and worse prognosis were observed in patients with high expression of circ-DONSON (p<0.05). The proliferation and migration abilities of glioma cells in circ-DONSON silenced group were remarkably suppressed when compared with NC group (p<0.05). Additionally, FOXO3 expression was remarkably down-regulated in glioma cell lines and tissues. FOXO3 expression was negatively correlated with circ-DONSON expression. In addition, cell reverse experiment demonstrated that circ-DONSON and FOXO3 can regulate each other, thereby together affecting the malignant progression of glioma.

CONCLUSIONS

Circ-DONSON was remarkably associated with lymph node or distant metastasis, as well as poor prognosis of patients with glioma. Furthermore, it promoted the metastasis of glioma cells via regulating FOXO3.

Estrogen enhances the expression of a growth-associated long noncoding RNA in chicken liver via ERα

1. The long noncoding RNA lncGLM is significantly differentially expressed in the livers of peak-laying hens compared with that in the livers of pre-laying hens, but its potential biological role and expression regulation are unclear.2. To explore the potential biological function of lncGLM, single nucleotide polymorphism (SNP) detection and association analysis were carried out in the Gushi×Anka F₂ resource population.3. The tissues and spatiotemporal expression characteristics of lncGLM were analysed by real-time quantitative PCR. The effects of 17β-oestradiol on the expression of lncGLM expression were analysed through in vitro and in vivo experiments.4. The results showed that a g.19069338 T > C SNP was present in lncGLM. Association analysis revealed that lncGLM was significantly associated with body slanting length at 12 weeks, body weight at 12 weeks, shank length at four weeks, chest depth at eight weeks, pelvic width at 12 weeks, eviscerated weight, head weight, pancreas weight, pectoralis weight, leg muscle weight, muscular stomach weight rate, pancreas weight rate, carcase weight, aspartate aminotransferase, creatinine and pectoral muscle water loss rate.5. The expression of lncGLM in the liver was higher than that in other sampled tissues. In addition, the expression of lncGLM in the liver was significantly higher in the peak-laying period than at the pre-laying period. Both in vitro and in vivo experiments showed that lncGLM expression was regulated by 17β-oestradiol via oestrogen receptor alpha (ER-α). These results demonstrated that the chicken lncGLM gene is highly expressed in liver tissue and regulated by oestrogen through ER-α.

[DNA double-strand breaks repair capacity and risk of differentiated thyroid cancer: a case-control study]

Objective: To study the influencing factors of DNA double-strand breaks (DSB) repair capacity and relationship with differentiated thyroid cancer (DTC). Methods: A total of 140 patients with thyroid diseases admitted to the Henan Cancer Hospital from January 2020 to March 2020 were retrospectively analyzed, including 26 males and 114 females, aged from 18 to 78 years old. According to the pathological results, the patients were divided into DTC group (90 cases) and control group or benign thyroid nodules (BTN) group (50 cases). The DSB repair ability of peripheral blood T lymphocytes was measured by flow cytometry. The data of two groups were compared by Wilcoxon rank sum test to evaluate the relationship between DSB repair ability and the risk of DTC. According to the median repair ability of DSB in BTN group, the repair ability of DSB was divided into high and low categories, and the factors influencing the repair ability of DSB were analyzed by Logistic regression method. SPSS 22.0 software was used to analyze the data. Results: The DSB repair capacity was 27.87% in DTC group and 36.75% in BTN group, with significant difference (Z=-3.999,P<0.05). Logistic regression analysis suggested that patients with thyroid cancer had lower DSB repair capacity than patients without cancer (OR=2.245; 95%CI: 1.067-4.725; P=0.033), and patients with a history of radiation exposure had a reduced DSB repair capacity (OR=2.698; 95%CI: 1.271-5.725, P=0.010). Conclusion: The risk of DTC increases in patients with low DSB repair capacity. Radiation exposure is a risk factor for the reduction of DSB repair capacity.

[Analysis of genetic characteristics in two Chinese children of type Ⅱ Waardenburg syndrome]

Objective: To screen and analyze the mutations of MITF gene in two children of type Ⅱ Waardenburg syndrome (WS2) from different families in Yunnan,China,and to explore the possible molecular pathogenesis. Methods: With informed consent, medical history collection, physical examinations, audiological evaluation, and high resolution computer tomography (HRCT) scan of temporal bone were performed on the two WS2 probands and their family members. Genomic DNA was extracted from peripheral blood of all individuals. The coding regions including all exons, part of introns and promoters of MITF, PAX3, SOX10, SNAI2, END3, ENDRB, and KITLG genes were sequenced by high-throughput sequencing. According to the results of high-throughput sequencing, pathogenic mutations detected in the probands and their parents were verified by Sanger sequencing. Results: The proband 1 carried c.641_643delGAA mutation in the 7th exon of MITF gene, which was a frame-shift mutation resulting in an amino acid change of p.214delR. It was a de novo mutation as the parents of proband 1 showed no variation on this site. The proband 2 carried heterozygous loss of the large fragment ranging from exon 1 to exon 9 of MITF gene, which defected the function of MITF protein. Conclusion: Genetic examinations provide important evidence for diagnosis of Waardenburg syndrome. Heterozygous mutation c.641_643delGAA and heterozygous loss of the large fragment ranging from exon 1 to exon 9 of MITF gene might be the molecular pathogenesis of the two WS2 probands in this study.

[Clinical features and interventional bronchoscopic treatment of primary airway tumor in 8 children]

Objective: To summarize the clinical manifestations and to evaluate the feasibility of therapeutic bronchoscopy in pediatric primary airway tumors. Methods: The clinical data of 8 children presented with airway tumors in Beijing Children's Hospital from November 2016 to March 2018 were retrospectively analyzed. Descriptive analysis was used to summarize the outcome and prognosis of these children after interventional bronchoscopy. Results: Among the 8 children, 5 were male and 3 were female, aged from 4 years and 8 months to 9 years and 2 months. The main clinical manifestations were cough and wheezing in 6 cases, hemoptysis in 3 cases and recurrent pulmonary infection in 2 cases, and none of them had lymph node metastasis and extra-pulmonary metastasis. All 8 children underwent bronchoscopic resection of the tumors, and the 4 children with blood-rich tumors had bronchial artery embolization at the blood supply site before the resection. No major bleeding or pneumothorax occurred during or after the operation. Four cases had low grade malignant bronchial mucoepidermoid carcinoma, 2 had inflammatory myofibroblastoma, and the rest two had pleomorphic adenoma and bronchial smooth muscle spindle cell tumor. Postoperative follow-up lasted 2 to 4 years, and 3 had tumor recured. Among the 3 cases, 2 had inflammatory myofibroblastoma who underwent surgical resection of the lesion and combined chemotherapy, respectively; and one had mucoepidermoid carcinoma who was under follow-up after interventional cryotherapy. Conclusions: The clinical manifestations of primary airway tumors in children are atypical. The main clinical manifestations are dry cough, wheezing, recurrent pulmonary infection and hemoptysis. Interventional bronchoscopy is a feasible choice for the treatment of pediatric airway tumors.

Validation of superior reference genes for qRT-PCR and Western blot analyses in marine Emiliania huxleyi-virus model system

AIMS

To search for a set of reference genes for reliable gene expression analysis in the globally important marine coccolithophore Emiliania huxleyi-virus model system.

METHODS AND RESULTS

Fifteen housekeeping genes (CDKA, CYP15, EFG3, POLAI, RPL30, RPL13, SAMS, COX1, GPB1-2, HSP90, TUA, TUB, UBA1, CAM3 and GAPDH) were evaluated for their stability as potential reference genes for qRT-PCR using ΔCt, geNorm, NormFinder, Bestkeeper and RefFinder software. CDKA, TUA and TUB genes were tested as loading controls for Western blot in the same sample panel. Additionally, target genes associated with cell apoptosis, that is metacaspase genes, were applied to validate the selection of reference genes. The analysis results demonstrated that putative housekeeping genes exhibited significant variations in both mRNA and protein content during virus infection. After a comprehensive analysis with all the algorithms, CDKA and GAPDH were recommended as the most stable reference genes for E huxleyi virus (EhV) infection treatments. For Western blot, significant variation was seen for TUA and TUB, whereas CDKA was stably expressed, consistent with the results of qRT-PCR.

CONCLUSIONS

CDKA and GAPDH are the best choice for gene and protein expression analysis than the other candidate reference genes under EhV infection conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

The stable internal control genes identified in this work will help to improve the accuracy and reliability of gene expression analysis and gain insight into complex E. huxleyi-EhV interaction regulatory networks.

Knockdown of long noncoding RNA DLX6-AS1 inhibits migration and invasion of thyroid cancer cells by upregulating UPF1

OBJECTIVE

Recently, long non- coding RNAs (lncRNAs) have attracted much attention for their roles in tumor progression. The aim of this study was to investigate the exact role of lncRNA DLX6 antisense RNA 1 (DLX6-AS1) in the development of thyroid cancer (TC), and to explore the underlying mechanism.

PATIENTS AND METHODS

DLX6-AS1 expression in both TC cells and tissue samples was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, transwell assay and wound healing assay were conducted. QRT-PCR and Western blot assay were used to explore the underlying mechanism. Furthermore, the function of DLX6-AS1 was identified in vivo.

RESULTS

DLX6-AS1 expression level in TC tissues was significantly higher than that of the corresponding normal tissues. Moreover, TC cell migration and invasion were markedly inhibited after DLX6-AS1 was knocked down in vitro. The mRNA and protein expressions of UPF1 were both remarkably up-regulated after knockdown of DLX6-AS1. Meanwhile, the expression level of UPF1 was negatively correlated with the expression of DLX6-AS1 in TC tissues. Furthermore, knockdown of DLX6-AS1 significantly inhibited tumor metastasis in vivo.

CONCLUSIONS

Knockdown of DLX6-AS1 could inhibit TC cell migration and invasion via upregulating UPF1, which might be a potential therapeutic target in TC.

Effect of Bifidobacterium animalis subsp. lactis MN-Gup on constipation and the composition of gut microbiota

Probiotics have been reported to be associated with the alleviation of constipation. The aim of this study was to detect and determine the effect of Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) on the alleviation of constipation in BALB/c mice and humans, and to elucidate the mechanisms underlying its effect by measuring changes in the concentration of short-chain fatty acids and the composition of microbes in human faeces. BALB/c mice were given MN-Gup by gavage for 14 days. On the 8^th day of this treatment, constipation was induced by the application of diphenoxylate via gavage. The results showed that MN-Gup significantly decreased the first black stool defecation time, and significantly increased black faecal wet weight, black faecal number and the gastric-intestinal transit rate (P<0.05), thereby relieving constipation. In humans, a randomised, double-blind, placebo-controlled trial was performed to investigate the effect of MN-Gup in adults with functional constipation. After 4 weeks of intervention with placebo or MN-Gup yogurt, constipation-related symptoms (including defecation frequency, stool consistency, straining and incomplete feeling during defecation) in the constipated subjects were significantly improved in the two groups, but not different between the groups at the end of the intervention. The concentration of acetate increased significantly in the MN-Gup group compared to the placebo group and before ingestion. Significant changes in the composition of gut microbiota were found after intake of MN-Gup yogurt when compared to placebo. The relative abundances of acetate-producing Bifidobacterium, Ruminoccaceae_UCG-002 and Ruminoccaceae_UCG-005 were significantly increased after intake of MN-Gup yogurt. These results showed that MN-Gup could relieve constipation related to increased acetate-producing Bifidobacterium, Ruminoccaceae_UCG-002 and Ruminoccaceae_UCG-005.

Automated measurement of broiler stretching behaviors under four stocking densities via faster region-based convolutional neural network

Stretching behavior is one of the broiler comfort behaviors that could be used for animal welfare assessment. However, there is currently no methodology for automatic monitoring of stretching behavior under representative production practices. The objectives of this study were to (1) develop a faster region-based convolutional neural network (faster R-CNN) stretching behavior detector for broiler stretching behavior detection, (2) evaluate broiler stretching behaviors under stocking densities (SDs) of 27 (27SD), 29 (29SD), 33 (33SD), and 39 kg/m² (39SD) and at weeks 4 and 5 of bird ages, and (3) examine the temporal and spatial distribution of broiler stretching behaviors. The results show that the precision, recall, specificity, and accuracy were over 86% on broiler stretching detection across all SDs and bird ages using the faster R-CNN stretching behavior detector. Broilers spent 230-533 sec stretching every day and showed more stretching behaviors under the 29SD, 33SD, and 39SD in week 4 and under the 29SD and 33SD in week 5, as compared to other SDs. They performed less stretching in a couple of hours after light ON and before light OFF but preferred to stretch in areas with less traffic and disturbance, that is, along the fences and away from the inspection aisle. It is concluded that the stretching behavior detector had acceptable performance in detecting broiler stretching, thus being a useful tool for broiler stretching detection. Broiler stretching behavior is affected by SD and bird age and shows temporal and spatial variations.

Pattern-recognition receptors in duck (Anas platyrhynchos): identification, expression and function analysis of toll-like receptor 3

1. Innate immunity provides the first line of defence against pathogenic organisms through a myriad of germline encoded receptors called pattern-recognition receptors (PRRs). Toll-like receptor (TLR) 3, as an important member of PRRs, is indispensable for host defence against viral infection by recognising virus-derived RNAs. However, little is known about the structure and function of TLR3 in ducks (Anas platyrhynchos), a natural host for the avian influenza virus.2. This study cloned the full-length cDNA of duck TLR3 using reverse transcription polymerase chain reaction (RT-PCR) with rapid amplification of cDNA ends (RACE). The cDNA sequence of duck TLR3 was 4046 bp in length and encoded 895 amino acids. Multiple sequence alignment showed that duck TLR3 shared high similarity with that from other vertebrates.3. Quantitative real-time PCR (qRT-PCR) analysis suggested that TLR3 mRNA was constitutively expressed in all tissues tested, having higher levels in the kidney, liver, breast muscle, ovary and heart. After stimulation with viral- or bacterial-mimics, including LPS, poly(I:C), pam3CSK4, FLS-1, FLA-ST and R848, the TLR3 transcript was significantly upregulated. Meanwhile, overexpression of duck TLR3 significantly promoted the transcription of IFN-β, IRF7, TRIF, Mx, STAT1 and STAT2 mRNA after stimulation with poly(I:C).4. These results suggested that TLR3 play an important role in resistance against viral and bacterial infections in ducks.

Evaluation of an accelerated 3D modulated flip-angle technique in refocused imaging with an extended echo-train sequence with compressed sensing for imaging of the knee: comparison with routine 2D MRI sequences

AIM

To accelerate the acquisition of high-resolution magnetic resonance imaging (MRI) by using the three-dimensional (3D) matrix sequence with compressed sensing and to compare it with conventional two-dimensional (2D) proton-density (PD) and fast spin-echo (FSE) sequences.

MATERIALS AND METHODS

3D matrix, 2D FSE, and PD sequences were acquired from 68 participants using 3 T magnetic resonance imaging (MRI). Two radiologists scored image quality independently on a four-point scale. The structural similarity index (SSIM), and signal- (SNRs) and contrast-to-noise ratios (CNRs) of different anatomical structures of the knee were assessed and compared between sequences using Wilcoxon signed-rank tests and Cohen's kappa.

RESULTS

The median acquisition time reduction was 44.5%. There was a substantial to perfect agreement for the rating between the 3D matrix FSE and 2D FSE or PD sequences when evaluating cartilage, subchondral bone, and ligaments (κ=0.783-872, p>0.05). The mean SSIM values between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences was 0.994 and 0.971, respectively, which are acceptable. No significant differences were found in SNR between the 3D matrix FSE and 2D FSE, and between the 3D matrix PD and 2D PD sequences, even though the SNR appeared to be higher on routine 2D sequences. The CNR of subchondral bone-meniscus, subchondral bone-joint fluid, and meniscus-joint fluid did not differentiate significantly between the 3D matrix sequence and routine 2D sequences.

CONCLUSIONS

3D matrix reduced the acquisition time in routine clinical knee MRI without the loss in image quality, SNR, and CNR.

Retroperitoneal totally endoscopic prosthetic repair of primary lumbar hernia

PURPOSE

A primary lumbar hernia is a rare entity that requires surgical management, but the preferred technique has not been established. We herein describe a standardized and reproducible retroperitoneal totally endoscopic prosthetic (TEP) repair technique for primary lumbar hernias.

METHODS

Ten adult patients with primary lumbar hernias underwent retroperitoneal TEP repair from February 2019 to July 2020. A sufficient retroperitoneal space was established to accommodate a non-coated polypropylene mesh to reinforce the weakened flank area, and hernia content reduction and defect closure were then performed. The patients' clinical data were prospectively collected and analyzed.

RESULTS

Nine patients had a primary superior lumbar hernia and one patient had a primary diffuse lumbar hernia. All operations were successfully performed without serious intraoperative complications. The mean defect area was 6.4 ± 2.8 cm² (range 4-12 cm²), and the mean mesh area was 144.6 cm² (range 130-180 cm²). The average operative time (skin to skin) was 49.0 ± 5.7 min (range 40-60 min), and intraoperative bleeding was minimal. The mean visual analog pain scale score at rest on the first postoperative day was 2.2 (range 2-3). The average length of postoperative stay was 1.5 days (range 1-2 days). No serious postoperative complications occurred. No recurrence, chronic pain, or mesh infection occurred during a mean follow-up period of 7.5 months.

CONCLUSIONS

The retroperitoneal TEP repair for primary lumbar hernias is safe, efficient, and reproducible. Anti-adhesive coated meshes and fixation tackers are not required, making this a cost-effective procedure that is worthy of recommendation.

[Clinical, myopathological and genetic features of two Chinese families with paramyotonia congenita]

Objective: To investigate the clinical, myopathological and genetic mutation characteristics in two Chinese families with paramyotonia congenita (PMC). Methods: Clinical manifestations, electrophysiology, muscle pathology and gene sequencing of two Chinese families with PMC were analyzed retrospectively. Results: Family 1 involved 12 patients in 4 consecutive generations and family 2 involved only 1 patient in 3 generations. The onset of symptoms in all patients started at early childhood. Both probands presented with myotonia triggered by cold and paroxysmal weakness. However, the other 11 patients in family 1 only manifested cold-induced myotonia. Serum creatine kinase (CK) was slightly elevated between attacks of weakness in the 2 probands, and was even greater than 10 000 U/L during the episodes of weakness in the second proband, whose lower limb MRI revealed edema in bilateral medial gastrocnemius. Electromyography showed diffuse myotonia discharge and myogenic impairment in both probands, and myotonia discharge in the first proband's mother. Muscle pathology of both probands showed mild myopathic changes, and tube aggregation was occasionally observed in the second one. Genetic testing revealed a maternally inherited heterozygous R1448H mutation of SCN4A gene in the first proband and part of his family. A novel heterozygous R1448G mutation of SCN4A gene was reported in the second proband. Conclusions: Cold-triggered myotonia with or without paroxysmal weakness are the common characteristics of PMC. Myotonic potential and myogenic impairment can be tested in electromyography. The p.R1448G mutation is a new missense mutation.

[Treatment of proximal humeral fractures in elderly patients with intramedullary nail and locking plate]

Objective: To compare the effect of intramedullary nail and locking plate in the treatment of proximal humeral fractures in the elderly. Methods: A total of 37 elderly patients with proximal humeral fractures were selected from April 2016 to June 2018 in Tianjin Hospital, including 13 males and 24 females, aged (66±5) years. The patients were divided into observation group (17 cases) and control group (20 cases) according to the random number table, and were treated with multiloc intramedullary nail and locking plate respectively. The operation time, blood loss, healing time of fractures, visual analogue scale of pain, Neer shoulder function score were recored and compared between the two groups. The data were compared with t test between the two groups. Results: The operation time of the observation group was shorter than that of the control group ((72±7) min vs (89±9) min, t=6.365, P<0.05); the intraoperative bleeding volume was lower than that of the control group ((56±6) ml vs (74±8) ml, t=7.923, P<0.05). The superior rate of shoulder function was 94.1%(16/17) in the observation group and 90.0%(18/20) in the control group (χ(2)=0.209, P>0.05). The VAS score of the observation group was lower than that of the control group on the first day after operation (t=4.706, P<0.05); the Neer shoulder function score of the observation group was higher than that of the control group on the sixth month after operation (81±8 vs 76±8, t=2.156, P<0.05). Six months after the operation, the valgus angle (19.21°±2.88°) of the observation group was larger than that of the control group (16.32°±2.63°, t=3.189, P<0.05), the humeral head varus angle (3.57°±0.47°), the humeral neck stem angle (139°±10°) was smaller than that of the others (5.24°±1.26°), (146°±13°) (t=5.159, 2.258, both P<0.05). There was no significant difference in shoulder function score and complication rate 12 months after operation between the two groups (both P>0.05). Conclusion: Both intramedullary nailing and locking plate can achieve better results in the treatment of proximal humeral fractures in the elderly, but the operation time of intramedullary nailing is shorter, the pain after operation is lighter and the recovery is faster.

Linoleic acid and α-linolenic acid inhibit conjugative transfer of an IncX4 plasmid carrying mcr-1

AIMS

The aim of this study was to determine the effects of unsaturated fatty acids on clinical plasmids.

METHODS AND RESULTS

Two unsaturated fatty acids, linoleic acid (LA) and α-linolenic acid (ALA) at final concentration 0, 0·03, 0·3 and 3 mmol l^-1 , respectively, were used to assess the effects on conjugative transfer of a mcr-1-harbouring plasmid pCSZ4 (IncX4) in conjugation experiment. The inhibitory mechanisms were analysed by molecular docking and the gene expression of virB11 was quantitated by qRT-PCR. Target plasmid diversity was carried out by TrwD/VirB11 homology protein sequence prediction analysis. Our results showed that LA and ALA inhibit plasmid pCSZ4 transfer by binding to the amino acid residues (Phe124 and Thr125) of VirB11 with dose-dependent effects. The expression levels of virB11 gene were also significantly inhibited by LA and ALA treatment. Protein homology analysis revealed a wide distribution of TrwD/VirB11-like genes among over 37 classes of plasmids originated from both Gram-negative and Gram-positive bacteria.

CONCLUSIONS

This study demonstrates representing a diversity of plasmids that may be potentially inhibited by unsaturated fatty acids.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our work reported here provides additional support for application of curbing the spread of multiple plasmids by unsaturated fatty acids.

Enhancement of immune responses by co-administration of bacterial ghosts-mediated Neisseria gonorrhoeae DNA vaccines

AIM

Gonorrhoea remains a leading public health burden and the development of vaccine against gonorrhoea becomes more urgent. Here, a novel Neisseria gonorrhoeae DNA vaccine delivered by Salmonella enteritidis ghosts was developed and the immune responses of the vaccine candidate were evaluated.

METHODS AND RESULTS

Neisseria gonorrhoeae nspA gene was cloned into the pVAX1 vector. The constructed recombinant plasmid pVAX1-nspA was loaded into the lyophilized SE ghosts to produce SE ghosts (pVAX1-nspA). Then, the immune responses induced by SE ghosts (pVAX1-nspA) alone and co-administrated with SE ghosts (pVAX1-porB) were evaluated in mouse model. Co-administered SE ghosts (pVAX1-nspA) and SE ghosts (pVAX1-porB) could elicited significantly higher levels of specific IgG antibody responses and lymphocyte proliferative responses than the control groups. Furthermore, the group co-administered SE ghosts (pVAX1-nspA) and SE ghosts (pVAX1-porB) had the highest bactericidal antibody titres.

CONCLUSIONS

Co-administration of SE ghosts (pVAX1-nspA) and SE ghosts (pVAX1-porB) elicited significant specific humoral and cellular immune responses.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the potential of co-administration of SE ghosts (pVAX1-nspA) and SE ghosts (pVAX1-porB) as an attractive vaccination regimen for gonorrhoea.

Dust mite-derived Enterobacterial fimbriae H protein enforces the allergen specific immunotherapy in asthma mice

BACKGROUND

The mite alimentary canal contains plenty of microbiota. It is accepted that some of the microbial products function as adjuvants to speed up immune responses.

OBJECTIVES

We identified five bacterial proteins from dust mite, and Enterobacterial fimbriae H (FimH) was one of them. This study aims to test a hypothesis that the FimH protein enforces immunotherapy in asthmatic mice.

METHODS

Asthmatic mice were treated by allergen specific immunotherapy (ASIT) with rDer f1/f2 or rDer f1/f2 plus FimH. Changes in inflammatory cell infiltration, airway hyperreactivity, frequency of Tregs, splenic CD4⁺IFN-γ⁺ cells, and serum levels of TGF-β, IL-10, IL-13 and IL-17A of asthmatic mice were checked.

RESULTS

ASIT with rDer f1/f2 plus FimH reduced inflammatory cell infiltration, airway hyperreactivity (AHR), and levels of IgE and IgG1 compared to ASIT with rDer f1/f2 alone, but the levels of IgG2a increased. Asthmatic mice that underwent ASIT with rDer f1/f2 plus FimH showed increased frequency of Tregs, splenic CD4⁺IFN-γ⁺ cells, serum levels of TGF-β and IL-10; and deceased splenic CD4⁺IL-4⁺ cells, and serum levels of IL-13 and IL-17A. In vitro study showed FimH triggered IL-10 expression in a concentration dependent manner and facilitated the differentiation of Tregs.

CONCLUSION

Used as an adjuvant, FimH enforces the effect of ASIT in asthmatic mice via augmenting Tregs.