[Application value of three-dimensional reconstruction in preoperative evaluation of precise hepatectomy for complex primary liver cancer]

Objective: To explore the application value of three-dimensional reconstruction of liver based on computer software in preoperative evaluation of precise hepatectomy for complex primary liver cancer. Methods: The clinical data of patients in Peking University People's Hospital Hepatobiliary surgery with complicated primary liver cancer from September 17, 2019 to December 20, 2020 were analyzed retrospectively. Preoperative enhanced CT/MR data of patients were collected, and 3D reconstruction of liver was performed in IQQA􀳏-3D Liver system. The liver volume of patients was calculated, the size and location of tumor were described, and the relationship between tumor and intrahepatic bile duct, portal vein, hepatic artery and inferior vena cava was described. Preoperative decision-making and treatment plan were made to compare the compliance of the actual operation plan with the planned operation plan under the guidance of three-dimensional reconstruction. Results: Among all 10 patients, there were 6 males and 4 females, aged 36 to 75 years. There were 6 cases of Child-Pugh grade A and 4 cases of B liver function. There were 5 cases of portal vein variation and 5 cases of hepatic artery variation. The range and M(Q₁,Q₃)of actual liver volume measured by 3D reconstruction in 10 patients was 895- 2 477 cm³ and [1 444(1 001, 1 854)] cm³;the nodule volume was 7-1 808 [133(50, 566)] cm³;the nodule volume in the liver was 0.8%-73.0% [11.0(3.3,32.7)]% and the number of suspected lesions was 1-7. In the end, 6 patients received surgical treatment;3 received chemotherapy, and 1 received conservative treatment. The preoperative three-dimensional reconstruction of liver anatomy and tumor location of the patients receiving surgical treatment were basically consistent with the intraoperative situation. There was no case of liver failure or death during perioperative period. Conclusion: In the preoperative evaluation of precise hepatectomy for complex primary liver cancer, 3D reconstruction can improve the rationality of treatment and the surgeon's understanding of the anatomical characteristics of the liver, so as to select the best treatment for patients, which has great application value.

Accurate prediction and genome-wide association analysis of digital intramuscular fat content in longissimus muscle of pigs

Intramuscular fat (IMF) content is a critical indicator of pork quality that affects directly the purchasing desire of consumers. However, to measure IMF content is both laborious and costly, preventing our understanding of its genetic determinants and improvement. In the present study, we constructed an accurate and fast image acquisition and analysis system, to extract and calculate the digital IMF content, the proportion of fat areas in the image (PFAI) of the longissimus muscle of 1709 animals from multiple pig populations. PFAI was highly significantly correlated with marbling scores (MS; 0.95, r²  = 0.90), and also with IMF contents chemically defined for 80 samples (0.79, r²  = 0.63; more accurate than direct analysis between IMF contents and MS). The processing time for one image is only 2.31 s. Genome-wide association analysis on PFAI for all 1709 animals identified 14 suggestive significant SNPs and 1 genome-wide significant SNP. On MS, we identified nine suggestive significant SNPs, and seven of them were also identified in PFAI. Furthermore, the significance (-log P) values of the seven common SNPs are higher in PFAI than in MS. Novel candidate genes of biological importance for IMF content were also discovered. Our imaging systems developed for prediction of digital IMF content is closer to IMF measured by Soxhlet extraction and slightly more accurate than MS. It can achieve fast and high-throughput IMF phenotype, which can be used in improvement of pork quality.

FOXN2 suppresses the proliferation and invasion of human hepatocellular carcinoma cells

OBJECTIVE

The aim of this study was to explore the roles of FOXN2 (Fork head Box N2) in mediating the proliferation and invasion of hepatocellular carcinoma (HCC) cells.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to determine expression of FOXN2 in HCC tissues and cells. Transfection of plasmid containing FOXN2 was used to exogenously overexpress FOXN2 in vitro. Cell Counting Kit-8 (CCK-8) assay and transwell assay were applied to detect the proliferation and invasion of HCC cells, respectively.

RESULTS

FOXN2 expression decreased significantly in both HCC tissues and cells (p<0.05). Upregulation of FOXN2 significantly inhibited the proliferation and invasion of HCC cells (p<0.05).

CONCLUSIONS

FOXN2 acts as a regulator in the progression of HCC. Our findings suggest that FOXN2 may be a novel therapeutic monitoring and prognosis biomarker in HCC.

Relationship between electrocardiographic changes and EPO level in stable CAD patients with autonomic nerve functional damage

OBJECTIVE

To investigate the relationship between electrocardiographic changes and erythropoietin (EPO) level in stable coronary artery disease (CAD) patients with autonomic nerve functional damage.

PATIENTS AND METHODS

Clinical data of 96 stable CAD patients who were treated in our hospital from January 2017 to December 2019 were retrospectively analyzed. All patients were grouped according to whether autonomic nerve function damage was combined; the baseline characteristic data and the morphological characteristics of ECG scattergram were compared between 2 groups, and the relationship between ECG scattergram and EPO level & autonomic nerve function was analyzed.

RESULTS

The levels of EPO and red cell volume distributing width (RDW) in stable CAD patients with autonomic nerve dysfunction were significantly higher than that of CAD patients without autonomic nerve dysfunction (p<0.05). The length of scattergram in stable CAD patients with autonomic nerve dysfunction was significantly shorter than that of those without autonomic nerve dysfunction (p<0.05). The cometary sign proportion of ECG scattergram in stable CAD patients with autonomic nerve dysfunction was significantly lower than that of stable CAD patients without autonomic nerve dysfunction (p<0.05). There was negative correlation between EPO levels and scattergram length in stable CAD patients with and without autonomic nerve dysfunction (r=0.44, p=0.02). There was no correlation between EPO levels and scatter width in stable CAD patients with and without autonomic nerve dysfunction (r=0.10, p=0.58). The results of binary logistic regression analysis showed that EPO level was the independent risk factor for the occurrence of autonomic dysfunction in patients with stable CAD (p<0.05). The length of scattergram was the independent protective factor of autonomic nerve function impairment in patients with stable CAD (p<0.05). The AUC of EPO level and scattergram was 0.74 and 0.72 respectively, both of which have similar prediction value.

CONCLUSIONS

The level of EPO in stable CAD patients with autonomic nerve dysfunction was related to the change of ECG; and the EPO level and scattergram length can be used to predict the occurrence risk of autonomic nerve dysfunction.

POS0885 HIGH INCIDENCE AND MORTALITY OF PNEUMOCYSTIS JIROVECI INFECTION IN ANTI-MDA5-ANTIBODY POSITIVE DERMATOMYOSITIS: EXPERIENCE FROM A SINGLE CENTER

Background:

Idiopathic inflammatory myopathies (IIM) was associated with a significantly higher risk of opportunistic infections that including Pneumocystis jiroveci pneumonia(PJP) which is potentially fatal opportunistic infection. However, no prior studies have evaluated the PJP infection in subtypes of IIM.

Objectives:

To investigate the incidence rate and mortality rate of PJP infection in subgroups of IIM patients according to myopathy specific antibodies.

Methods:

In the first part, we reviewed 463 consecutive patients with IIM retrospectively to analyze incidence of PJP infection. In the next part, we enrolled 30 consecutive PJP infection patients with any rheumatic disease was to identify the mortality rate and risk factors. Kaplan-Meier curve with log rank test was used to access differences in survival. Univariate and multivariate analyses were performed to identify prognostic factors using Cox regression.

Results:

We found that 12(7.5%) PJP cases occurred in 160 anti-MDA5-ab-positive DM patients, while only two (0.7%) PJP cases were found in 303 anti-MDA5-ab-negtive DM/PM patients(P < 0.05). PJP infection typically happened in the first two months of the treatment for anti-MDA5-ab-positive DM patients who have a significant decrease in the CD4+ T cell counts and Lymphocyte counts (P < 0.05). Only two (16.7%) anti-MDA5-ab-positive DM patients recover from PJP, with lethally higher mortality than those PJP infection with other rheumatic diseases (83.3% vs. 38.9%, P < 0.05). We found no association between the time to anti-PJP treatment and treatment outcomes in anti-MDA5-ab-positive DM; yet we confirmed in PJP infection with other rheumatic diseases that anti-PJP treatment within 6 days crucially increased the survival (P < 0.05).

Conclusion:

PJP infection has alarming high incidence and mortality in anti-MDA5-ab-positive DM patients. Unlike PJP infection with other rheumatic diseases, timely treatment for PJP doesn’t improve the prognosis of this particular subtype. Therefore, the necessity of further study of PJP prophylaxis treatment in anti-MDA5-ab-positive DM patients is verified.

References:

[1]Hsu CY, et al. Comparing the burdens of opportunistic infections among patients with systemic rheumatic diseases: a nationally representative cohort study. ARTHRITIS RES THER 2019, 21(1):211.

Acknowledgements:

The authors thank Dr. An Sun,

Disclosure of Interests:

None declared

POS0785 CHANGING EXPRESSION PROFILES OF LONG NONCODING RNAS, MIRNAS, MRNAS AND CIRCULAR RNAS IN LABIAL SALIVARY GLANDS OF PRIMARY SJÖGREN’S SYNDROME (PSS)

Background:

Primary Sjögren’s syndrome (pSS) is a relatively common autoimmune disease characterized by oral and ocular dryness. An increasing number of studies have revealed that long non-coding RNA (lncRNA), miRNA, mRNA and circular RNA (circRNA) contributes to the pathogenesis of autoimmune diseases.

Objectives:

To explore lncRNA, miRNA, mRNA and circRNA expression profiles in labial salivary glands (LSGs) in pSS patients and their biological functions in the regulation of pSS.

Methods:

The expression of 75,550 lncRNAs, 2,318 miRNA, 20,292 mRNAs and 6,877 circRNAs were determined in the LSG of six pSS patients and six healthy controls using microarray experiments. Validation was performed in pSS patients and controls using real-time PCR. LncRNA-mRNA co-expression and gene-pathway networks were constructed using bioinformatics software.

Results:

A total of 599 lncRNAs (upregulated: 279, downregulated: 320), 78 miRNAs (upregulated: 26, downregulated: 52), 615 mRNAs (upregulated: 590, downregulated: 25) and 160 mRNAs (upregulated: 110, downregulated: 50) were differentially expressed in the LSGs of pSS patients. Five of these lncRNAs were validated using real-time PCR. lncRNA HCP5, lncRNA SNHG5, lncRNA IFI44L, lncRNA CMPK2 were significantly upregulated and lncRNA TTYH1 were downregulated in pSS. GO and KEGG biological pathway analysis were performed to predict the functions of differentially expressed lncRNAs and co-expressed potential targeting genes. Subsequently, a ceRNA (lncRNA-miRNA-mRNA) network including 2320 ceRNA pairs was constructed based on predicted miRNAs shared by lncRNAs and mRNAs.

Conclusion:

The expression profile provided a systematic perspective on the potential functions of lncRNAs miRNAs, mRNAs and circRNAs in the pathogenesis of pSS. Therefore, this study will aid in the development of new diagnostic biomarkers and drug therapies.

References:

[1]Le Dantec C, Varin MM, Brooks WH, Pers JO, Youinou P, Renaudineau Y. Epigenetics and Sjogren’s syndrome.Curr Pharm Biotechnol. 2012 Aug;13(10):2046-53.

Disclosure of Interests:

None declared

Association between serum estradiol levels prior to progesterone administration in artificial frozen-thawed blastocyst transfer cycles and live birth rate: a retrospective study

OBJECTIVE

To study whether serum estradiol (E2) levels prior to progesterone administration in the artificial endometrial preparation (AEP) of frozen-thawed blastocyst transfer affect the live birth rate.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care academic medical centre.

POPULATION

A total of 3857 frozen-thawed blastocyst transfer cycles were divided into three groups: <200 pg/ml (n = 1676); 200-399 pg/ml (n = 1296); and ≥400 pg/ml (n = 885), based on the 25th (182.3 pg/ml) and 75th percentile (390.2 pg/ml) of serum E2 level prior to progesterone administration.

METHODS

Univariable and multivariable logistic regression analysis was performed.

MAIN OUTCOME MEASURES

The primary outcome of the study was the live birth rate and the secondary outcomes included clinical pregnancy rate, pregnancy loss rate, neonatal birthweight, Z-score, and small for gestational age (SGA).

RESULTS

Compared with the reference group, accounting for major covariates, the live birth rate significantly decreased in the '≥400 pg/ml' group (adjusted OR 0.71, 95% CI 0.59-0.85). Compared with the reference group, there was an association between the E2 level in the '≥400 pg/ml' group and a decrease in the clinical pregnancy rate (adjusted OR 0.74, 95% CI 0.61-0.89). Compared with the reference group, the pregnancy loss rate significantly increased in the '≥400 pg/ml' group (adjusted OR 1.45, 95% CI 1.08-1.93). The E2 levels did not affect neonatal birthweight, Z-score, and SGA among singletons.

CONCLUSIONS

High serum E2 levels prior to progesterone administration in AEP are associated with a decreased live birth rate after frozen-thawed blastocyst transfer.

TWEETABLE ABSTRACT

High serum E2 levels prior to progesterone administration in artificial FET are associated with a decreased live birth rate after frozen-thawed blastocyst transfer.

Pcsk9 Knockout Aggravated Experimental Apical Periodontitis via LDLR

Apical periodontitis (AP), an inflammatory lesion around the apex of tooth roots, is mostly caused by dental pulp infection. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a vital role in regulating cholesterol homeostasis by targeting low-density lipoprotein receptor (LDLR) and participates in bacterium-induced chronic periodontitis. However, the roles of PCSK9 in AP are unknown. Here, we investigated its role in AP by using Pcsk9^-/- mice. Micro-computed tomography scanning and histological staining revealed that the periapical bone loss of Pcsk9^-/- mice was greater than that of wild-type (WT) mice, and increased expression of inflammation-related factors tumor necrosis factor α (TNF-α) and interleukin (IL)-6 was also observed. Immunofluorescence staining and quantitative real-time polymerase chain reaction showed PCSK9 expression in bone marrow macrophages (BMMs) was increased after treatment with lipopolysaccharide (LPS). This finding was consistent with the in vivo results that the expression level of PCSK9 in exposed WT mice increased compared with that in unexposed WT mice. After LPS challenge, the expression levels of TNF-α, IL-1β, and IL-6 in BMMs were increased, and Pcsk9 knockout aggravated the expression of these inflammatory factors. The number of osteoclasts positive for tartrate-resistant acid phosphatase staining around the apical lesion in Pcsk9^-/- mice was higher than that in WT mice. Then BMMs underwent the osteoclast differentiation. Pcsk9 knockout BMMs induced increased and larger osteoclasts. While this effect of Pcsk9 knockout was abolished by the addition of Ldlr small interfering RNA, revealing that Pcsk9 knockout increased osteoclastogenesis was dependent on the LDLR. Immunohistochemistry staining showed increased expression level of LDLR in exposed Pcsk9^-/- periapical areas. In vitro experiments showed that LPS promoted the expression level of LDLR in Pcsk9^-/- BMMs and increased osteoclast formation ability, indicating that LPS promoted the elevation of osteoclasteogenesis caused by the Pcsk9 knockout. In conclusion, Pcsk9 deficiency aggravated the inflammatory response and promoted the osteoclastogenesis in an LDLR-dependent manner in AP experimental mice.

rs1840680 single nucleotide polymorphism in Pentraxin 3: a potential protective biomarker of severe community-acquired pneumonia

Objective

Single nucleotide polymorphisms (SNPs) of pentraxin 3 (PTX3) are associated with various outcomes of lung infections. This study aimed to analyze the relationship between PTX3 polymorphisms and the severity of community-acquired pneumonia (CAP).

Methods

This is a retrospective case-control study comprising 43 patients with severe CAP (SCAP) and 97 patients with non-severe CAP. Three SNPs in the PTX3 gene (rs2305619, rs3816527, and rs1840680) from peripheral blood samples were genotyped by real-time polymerase chain reaction. The association between each SNP and the CAP severity was analyzed by logistic regression analysis.

Results

We found that the rs1840680 polymorphism was significantly associated with CAP clinical severity. However, no such association was observed for the genotypes and allele frequencies of rs2305619 or rs3816527. The PTX3 rs1840680 AG genotype was an independent factor for a lower risk of SCAP after multivariate logistic regression analysis. Male sex and coronary heart disease were associated with an increased risk of SCAP.

Conclusions

The PTX3 rs1840680 AG genotype was found to be associated with a lower risk of SCAP, and may serve as a potential protective biomarker to help clinical judgment and management.

Theabrownin Induces Cell Apoptosis and Cell Cycle Arrest of Oligodendroglioma and Astrocytoma in Different Pathways

Theabrownin (TB), a natural compound present in the fresh leaves of green tea, is a potential antitumor agent. However, so far whether and how TB affects glioma is unclear. In this study, we investigated the effect of TB on astroglioma and oligodendroglioma cells. Surprisingly, TB significantly reduced the viabilities of HOG and U251 cells in a dose-dependent manner, which was accompanied by the upregulation of active-Casp-3, Bax, and PTEN; meanwhile, the antiapoptotic gene Bcl-2 was downregulated. In addition, TB treatment induced cell cycle arrest at the G1 and G2/M phases in HOG and U251 cells, respectively. TB treatment caused the downregulating of c-myc, cyclin D, CDK2, and CDK4 and upregulating of p21 and p27 in the HOG cell, while TB increased P53, p21, and p27 levels and decreased the levels of cell cycle regulator proteins such as CDK and cyclin A/B in the U251 cells. Therefore, the c-myc- and P53-related mechanisms were proposed for cell cycle arrest in these two glioma cell lines, respectively. Overall, our findings indicated that TB could be a novel candidate drug for the treatment of gliomas.

The expression and clinical significance of B7-H3 and miR-145 in lung cancer patients with malignant pleural effusion

OBJECTIVE

To investigate the expression and clinical significance of costimulatory molecule B7-H3 and microRNA-145 (miR-145) in lung cancer patients with malignant pleural effusion.

PATIENTS AND METHODS

A total of 100 cases of patients with lung cancer who admitted to our hospital for treatment from March 2017 to September 2018 were selected. Forty-nine cases of patients diagnosed with malignant pleural effusion were included in the study group, and 51 cases with benign pleural effusion in the control group. The content of B7-H3 in pleural effusion of the two groups was detected by enzyme-linked immunosorbent assay (ELISA), and the expression of miR-145 in pleural effusion of the two groups was analyzed by Real-time quantitative PCR (qRT-PCR). The relationships between the expressions of B7-H3 and miR-145 and the clinicopathological characteristics were analyzed. The diagnostic value of B7-H3 and miR-145 in lung cancer was analyzed.

RESULTS

The expression level of B7-H3 in the study group was significantly higher than that in the control group (p<0.050), while the expression level of miR-145 was significantly lower than that in the control group (p<0.050). The expression levels of B7-H3 and miR-145 in the study group were correlated with lymph node metastasis, differentiation degree of lung cancer and TNM stage (p<0.001). The sensitivity and specificity of miR-145 in single diagnosis of lung cancer were 64.71% and 79.59%, respectively. The sensitivity and specificity of B7-H3 in single diagnosis of lung cancer were 80.39% and 61.22%, respectively.

CONCLUSIONS

B7-H3 and miR-145 are abnormally expressed in lung cancer, and are closely related to the lymphatic metastasis, differentiation degree and TNM stage of lung cancer. They may be potential markers for the diagnosis of malignant pleural effusion in lung cancer in the future.

Bronchiectasis is associated with delayed diagnosis and adverse outcomes in the New Zealand Common Variable Immunodeficiency Disorders cohort study

Common variable immunodeficiency disorders (CVID) are multi-system disorders where target organ damage is mediated by infective, autoimmune and inflammatory processes. Bronchiectasis is probably the most common disabling complication of CVID. The risk factors for bronchiectasis in CVID patients are incompletely understood. The New Zealand CVID study (NZCS) is a nationwide longitudinal observational study of adults, which commenced in 2006. In this analysis, the prevalence and risk factors for bronchiectasis were examined in the NZCS. After informed consent, clinical and demographic data were obtained with an interviewer-assisted questionnaire. Linked electronic clinical records and laboratory results were also reviewed. Statistical methods were applied to determine if variables such as early-onset disease, delay in diagnosis and increased numbers of infections were associated with greater risk of bronchiectasis. One hundred and seven adult patients with a diagnosis of CVID are currently enrolled in the NZCS, comprising approximately 70% of patients known to have CVID in New Zealand. Fifty patients (46·7%) had radiologically proven bronchiectasis. This study has shown that patients with compared to those without bronchiectasis have an increased mortality at a younger age. CVID patients with bronchiectasis had a greater number of severe infections consequent to early-onset disease and delayed diagnosis. Indigenous Māori have a high prevalence of CVID and a much greater burden of bronchiectasis compared to New Zealand Europeans. Diagnostic latency has not improved during the study period. Exposure to large numbers of infections because of early-onset disease and delayed diagnosis was associated with an increased risk of bronchiectasis. Earlier diagnosis and treatment of CVID may reduce the risk of bronchiectasis and premature death in some patients.

[Clinical efficacy of stent-assisted coil embolization for recurrent intracranial bifurcation aneurysms]

Objective: To evaluate the safety and efficacy of stent-assisted coil embolization in patients with recurrent intracranial bifurcation aneurysms,after initial simple coiling or microsurgical clipping. Methods: Clinical data of 20 patients with recurrent intracranial bifurcation aneurysms who initially underwent simple coiling or surgical clipping and subsequently re-treated by stent-assisted coiling embolization at the Radiology Intervention Department of Huashan Hospital between March 2009 and November 2019 were collected and analyzed retrospectively.There were 9 males and 11 females,with a median age of 55.5 years (range:33 to 71 years),including 17 aneurysms initially treated with simple coiling and 3 treated with surgical clipping.All cases were re-treated with stent-assisted coiling,15 using a single stent and 5 employing two stents in a Y-configuration.Peri-and post-operative complications and outcomes were evaluated.Mann-Whitney U tests were performed to compare the follow-up duration between initial treatment and re-treatment.Student's t tests were used to compare the parent artery angles before re-treatment, after re-treatment and at the last follow-up. The parent artery angle was defined using the proximal main trunk and the stented branch. Results: Immediate complete occlusion (Raymond Ⅰ) was achieved in 18 aneurysms (90.0%) while 2 aneurysms (10.0%) had a residual neck (Raymond Ⅱ).The median follow-up time(M(Q_R)) was 8.5(16.3)months,which had no significantly different from the initial treatment follow-up duration (15.5(27.0)months)(U=157.7,P=0.25). During the follow-up period,2 aneurysms (10.0%) with immediate post-operative residual necks recanalized again,including 1 aneurysm re-treated with the Y-configuration stent.Symptomatic thromboembolic complications occurred in 6 patients,including 4 re-treated with the Y-configuration stent.No peri-operative hemorrhagic complications occurred,along with no operation-related permanent disability or death. The parent artery angle increased significantly from pre-operative(90.1±21.1)°to post-operative and the last follow-up ((115.4±28.9)° and (132.6±26.8)°);t=5.14,P<0.01;t=7.78,P<0.01). Conclusion: For recurrent intracranial bifurcation aneurysms after initial surgical clipping or simple coiling,stent assisted coil embolization is proved to be safe and can decrease recurrence rate.

[The Autism Spectrum Disorder Cohort-the sub-cohort of China National Birth Cohort]

Autism spectrum disorder (ASD), a representative disease of children's neurodevelopmental disorders, brings huge pressure and financial burden to families and society. It is of great significance to explore its etiology and pathogenesis. Therefore, we established an ASD Cohort based on the existing China National Birth Cohort (CNBC), which applied parallel design to recruit and follow up families who achieved pregnancy after receiving assisted reproductive technologies (ART) and families with spontaneous conception. The main aims of this study are to compare the incidence of ASD among children born after ART with those born under spontaneous pregnancy, and to evaluate the impact of ART on the neurobehavioral development of offspring. Additionally, with a variety of clinical and behavioral related information collected during pregnancy and at early life of offspring, we are able to investigate the risk factors associated with ASD comprehensively. This article briefly introduces the objectives, contents, preliminary progress, strength and limitations, as well as further prospects of the ASD cohort study, mainly focusing on the overall design and current progress.

STRAP reduces endoplasmic reticulum stress and apoptosis in cardiomyocytes and attenuates myocardial ischemia-reperfusion injury by activating PI3K/PDK1/Akt signaling pathway

OBJECTIVE

Myocardial ischemia-reperfusion injury (MIRI) is a common problem in heart-related diseases. The aim of this study was to explore the protective effects of STRAP on cardiomyocytes in the MIRI process and its mechanisms.

MATERIALS AND METHODS

We used SD rats to construct a MIRI model and increased the expression of STRAP in myocardial tissue by Entranster to detect the effect of STRAP on rat myocardial tissue. In addition, we cultured rat cardiomyocyte cell line H9c2 cells and constructed a hypoxia-reoxygenation model to detect the protective effect of STRAP on H9c2 cells. LY294002, an inhibitor of the PI3K/PDK1/Akt signaling pathway, was used to validate the mechanism by which STRAP protects cardiomyocytes.

RESULTS

Overexpression of STRAP significantly reduced the activity of MDA in myocardial tissue and increased the activity of SOD. STRAP also substantially lowered CK and LDH levels in rat serum and increased Na+-K+-ATPase and Ca2+-Mg2+-ATPase activity. In addition, overexpression of STRAP considerably reduced endoplasmic reticulum stress (ERS) and apoptosis levels in H9c2 cells. However, LY294002 attenuated the protective effect of STRAP on cardiomyocytes.

CONCLUSIONS

STRAP reduces ERS and apoptosis in cardiomyocytes by activating the PI3K/PDK1/Akt signaling pathway, thereby reducing myocardial MIRI.

A novel dentin bonding scheme based on extrafibrillar demineralization combined with covalent adhesion using a dry-bonding technique

Dentin bonding is a dynamic process that involves the penetration of adhesive resin monomers into the extrafibrillar and intrafibrillar demineralized collagen matrix using a wet-bonding technique. However, adhesive resin monomers lack the capacity to infiltrate the intrafibrillar space, and the excess water that is introduced by the wet-bonding technique remains at the bonding interface. This imperfectly bonded interface is inclined to hydrolytic degradation, severely jeopardizing the longevity of bonded clinical restorations. The present study introduces a dentin bonding scheme based on a dry-bonding technique, combined with the use of extrafibrillar demineralization and a collagen-reactive monomer (CRM)-based adhesive (CBA). Selective extrafibrillar demineralization was achieved using 1-wt% high-molecular weight (MW) carboxymethyl chitosan (CMCS) within a clinically acceptable timeframe to create a less aggressive bonding substance for dentin bonding due to its selectively extrafibrillar demineralization capacity. CMCS demineralization decreased the activation of in situ collagenase, improved the shrinking resistance of demineralized collagen, and thus provided stronger and more durable bonding than traditional phosphoric acid etching. The new dentin bonding scheme that contained CMCS and CBA and used a dry-bonding technique achieved an encouraging dentin bonding strength and durability with low technical sensitivity. This bonding scheme can be used to improve the stability of the resin-dentin interface and foster the longevity of bonded clinical restorations.