[Predictive value of left ventricular ejection fraction reserve assessed by SPECT G-MPI for major adverse cardiovascular event in patients with coronary artery disease].

Objective: To evaluate the prognostic value of left ventricular ejection fraction (LVEF) reserve assessed by gated SPECT myocardial perfusion imaging (SPECT G-MPI) for major adverse cardiovascular event (MACE) in patients with coronary artery disease. Methods: This is a retrospective cohort study. From January 2017 to December 2019, patients with coronary artery disease and confirmed myocardial ischemia by stress and rest SPECT G-MPI, and underwent coronary angiography within 3 months were enrolled. The sum stress score (SSS) and sum resting score (SRS) were analyzed by the standard 17-segment model, and the sum difference score (SDS, SDS=SSS-SRS) was calculated. The LVEF at stress and rest were analyzed by 4DM software. The LVEF reserve (ΔLVEF) was calculated (ΔLVEF=stress LVEF-rest LVEF). The primary endpoint was MACE, which was obtained by reviewing the medical record system or by telephone follow-up once every twelve months. Patients were divided into MACE-free and MACE groups. Spearman correlation analysis was used to analyze the correlation between ΔLVEF and all MPI parameters. Cox regression analysis was used to analyze the independent factors of MACE, and the optimal SDS cutoff value for predicting MACE was determined by receiver operating characteristic curve (ROC). Kaplan-Meier survival curves were plotted to compare the difference in the incidence of MACE between different SDS groups and different ΔLVEF groups. Results: A total of 164 patients with coronary artery disease [120 male; age (58.6±10.7) years] were included. The average follow-up time was (26.5±10.4) months, and a total of 30 MACE were recorded during follow-up. Multivariate Cox regression analysis showed that SDS (HR=1.069, 95%CI: 1.005-1.137, P=0.035) and ΔLVEF (HR=0.935, 95%CI: 0.878-0.995, P=0.034) were independent predictors of MACE. According to ROC curve analysis, the optimal cut-off to predict MACE was a SDS of 5.5 with an area under the curve of 0.63 (P=0.022). Survival analysis showed that the incidence of MACE was significantly higher in the SDS≥5.5 group than in the SDS<5.5 group (27.6% vs. 13.2%, P=0.019), but the incidence of MACE was significantly lower in the ΔLVEF≥0 group than in theΔLVEF<0 group (11.0% vs. 25.6%, P=0.022). Conclusions: LVEF reserve (ΔLVEF) assessed by SPECT G-MPI serves as an independent protective factor for MACE, while SDS is an independent risk predictor in patients with coronary artery disease. SPECT G-MPI is valuable for risk stratification by assessing myocardial ischemia and LVEF.

[Predictive value of the proportion of hibernating myocardium in total perfusion defect on reverse remodeling in patients with HFrEF underwent coronary artery bypass graft].

Objective: To evaluate the predictive value of the proportion of hibernating myocardium (HM) in total perfusion defect (TPD) on reverse left ventricle remodeling (RR) after coronary artery bypass graft (CABG) in patients with heart failure with reduced ejection fraction (HFrEF) by 99mTc-methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) combined with 18F-flurodeoxyglucose (FDG) gated myocardial imaging positron emission computed tomography (PET). Methods: Inpatients diagnosed with HFrEF at the Cardiac Surgery Center, Anzhen Hospital of Capital Medical University from January 2016 to January 2022 were prospectively recruited. MPI combined with 18F-FDG gated PET was performed before surgery for viability assessment and the patients received follow-up MPI and 18F-FDG gated PET at different stages (3-12 months) after surgery. Δ indicated changes (post-pre). Left ventricular end-systolic volume (ESV) reduced at least 10% was defined as RR, patients were divided into reverse remodeling (RR+) group and the non-reverse group (RR-). Binary logistic regression analysis was used to identify predictors of RR. Receiver operating characteristic (ROC) curve analysis was performed and the area under the curve (AUC) was calculated to assess the cut-off value for predicting RR. Additionally, we retrospectively enrolled inpatients with HFrEF at the Cardiac Surgery Center, Anzhen Hospital of Capital Medical University from January 2021 to January 2022 as the validation group, who underwent MPI and 18F-FDG gated PET before surgery. Echocardiography was performed before CABG and after CABG (3-12 months). In the validation group, the reliability of obtaining the cut-off value for the ROC curve was verified. Results: A total of 28 patients with HFrEF (26 males; age (56.9±8.7) years) were included in the prospective cohort. HM/TPD was significantly higher in the RR+ group than in the RR- group ((51.8%±17.9%) vs. (35.7%±13.9%), P=0.016). Binary logistic regression analysis revealed that HM/TPD was an independent predictor of RR (Odds ratio=1.073, 95% Confidence interval: 1.005-1.145, P=0.035). ROC curve analysis revealed that HM/TPD=38.3% yielded the highest sensitivity, specificity, and accuracy (all 75%) for predicting RR and the AUC was 0.786 (P=0.011). Meanwhile, a total of 100 patients with HFrEF (90 males; age (59.7±9.6) years) were included in the validation group. In the validation group, HM/TPD=38.3% predicted RR in HFrEF patients after CABG with the highest sensitivity, specificity and accuracy (82%, 60% and 73% respectively). Compared with the HFrEF patients in the HM/TPD<38.3% group (n=36), RR and cardiac function improved more significantly in the HM/TPD≥38.3% group (n=64) (all P<0.05). Conclusions: Preoperative HM/TPD ratio is an independent factor for predicting RR in patients with HFrEF after CABG, and HM/TPD≥38.3% can accurately predict RR and the improvement of cardiac function after CABG.

[Levels and trends of significant injury-caused deaths in the Chinese population, 2010-2019].

Objective: To analyze the level and changing trend of significant injury-caused deaths in the Chinese population from 2010 to 2019 and provide evidence for related intervention. Methods: Data on notable injury-caused deaths in areas under National Disease Surveillance Programs were collected from 2010 to 2019. Crude and standardized mortality rates of four significant injuries were calculated to describe the status of injury-caused deaths. The trend of changes in standardized mortality rates was analyzed using the Joinpoint regression model. Results: The overall trend of standardized mortality rate on an injury during 2010-2019 was consistently decreasing (AAPC=-3.5%, P<0.001) while the general direction of accidental fall standardized mortality rate was increasing (AAPC=1.0%, P=0.104). The standardized mortality rate for significant injuries fluctuated with age, increasing for those aged 50-79 years (AAPC=3.9% for the 50- group, AAPC=5.6% for the 60- group, and AAPC=4.6% for the 70- group, all P<0.001). The standardized mortality rates for all major injuries were higher in males than those in females, with road traffic accidents and drowning declining faster in males than that in females (AAPC=-5.3% in the male road traffic accident group, AAPC=-3.8% in the female road traffic accident group, AAPC=-4.0% in the male drowning group, AAPC=-3.5% in the female drowning group, all P<0.001), and suicide and sequelae declining faster in females than that in males (AAPC=-6.4% in female, AAPC=-4.7% in male, all P<0.001). The standardized mortality rate for significant injuries was higher in rural than that in urban areas and decreased faster than that in urban areas. The central region had the highest standardized mortality rate for suicide and sequelae. The western part had the highest standardized mortality rates for road traffic accidents, accidental falls, and drowning, with the fastest decline in road traffic accidents and drowning (AAPC=-5.3% in the road traffic accident group and AAPC=-5.3% in the drowning group, both P<0.001). Conclusions: The mortality rate from significant injuries in the Chinese population showed a continuous downward trend from 2010 to 2019, with a rebound in the standardized mortality rate from accidental falls in recent years among the elderly, males, rural residents, and central and western regions being the focus of future prevention and control.

[Confirmation and analysis of 2 398 positive results of cell-free fetal DNA].

Objective: To explore the clinical application value and accuracy of cell-free fetal DNA (cff-DNA) technique in prenatal screening. Methods: The results of quantitative fluorescent PCR (QF-PCR) and karyotype of amniotic fluid cells were analyzed retrospectively in 2 398 monocyesis pregnant women who had been amniocentesis at the First Affiliated Hospital of Zhengzhou University from May 2013 to December 2019, and the results of 359 cases who had been examined by single-nucleotide polymorphism array (SNP array). Results: Cff-DNA test of 2, 398 cases indicated 987 cases of trisomy 21, 351 cases of trisomy 18, 135 cases of trisomy 13, 566 cases of sex chromosome abnormality, and 359 cases of other chromosome abnormality. Chromosome karyotype analysis detected 826 cases of trisomy 21, 213 cases of trisomy 18, 17 cases of trisomy 13, 221 cases of sex chromosome abnormality, and 26 cases of other chromosome abnormality. The detection rate were 83.69% (826/987), 60.68% (213/351), 12.59% (17/135), 39.04% (221/566) and 7.24% (26/359), respectively. QF-PCR detected 1 046 cases of trisomy and 188 cases of sex chromosomes abnormality, and the detection rate was 99.05% (1 046/1 056) and 85.07% (188/221), respectively. Compared with the abnormal number detected by chromosome karyotype analysis, 10 cases of trisomeric chimerism and 24 cases of sex chromosome were missed by QF-PCR. Among the 359 other chromosomal abnormalities detected by SNP array, 64 cases were consistent with the results of cff-DNA, and the detection rate was 17.83% (64/359), which was 10.59% higher than the karyotype result. Conclusions: Karyotype analysis is the gold standard for diagnosing chromosomal abnormalities. QF-PCR could diagnose common chromosome aneuploidy rapidly and accurately, and it could be used as an auxiliary detection technique for karyotype analysis. The incidence of sex chromosome chimerism is high, so missed diagnosis should be warned. SNP array could be given priority to verify chromosome microdeletion or microduplication detected by cff-DNA.

LncRNA CRNDE promotes the development of Wilms' tumor by regulating microRNA-424.

OBJECTIVE: The aim of this study was to investigate the expression characteristics of lncRNA CRNDE in Wilms' tumor and to further investigate whether it could promote the development of Wilms' tumor via regulating microRNA-424. PATIENTS AND METHODS: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was performed to examine the expression level of CRNDE in tumor tissues and para-cancerous tissues of patients with Wilms' tumor. Meanwhile, the expression of CRNDE in Wilms' tumor cell lines was analyzed as well. CRNDE overexpression and knockdown models were constructed using lentivirus transfection in HFWT and 17-94 cell lines, respectively. Subsequently, cell counting kit-8 (CCK-8), cell colony formation, and transwell assays were performed to explore the influence of CRNDE on the biological functions of Wilms' tumor cells. Furthermore, luciferase reporter gene assay and cell reversal experiment were applied to explore the interplay between CRNDE and microRNA-424. RESULTS: RT-qPCR results revealed that the expression level of lncRNA CRNDE in tumor tissues of patients with Wilms' tumor was remarkably higher than that of adjacent normal tissues. Also, the difference was statistically significant (p<0.05). Compared with patients with low expression of CRNDE, the risk of lymph node metastasis was significantly higher in patients with high CRNDE expression (p<0.05). Similarly, compared with control group, the proliferation and metastasis abilities of cells in CRNDE knockdown group were remarkably down-regulated (p<0.05). However, opposite results were observed in CRNDE overexpression group. In addition, our results demonstrated that microRNA-424 expression was negatively correlated with CRNDE expression in Wilms' tumor tissues. Luciferase reporter gene assay indicated that CRNDE could be targeted by microRNA-424 through specific a binding site, further regulating the malignant progression of Wilms' tumor. CONCLUSIONS: CRNDE was highly expressed in Wilms' tumor tissue and cell lines. The expression of CRNDE was correlated with the incidence rate of lymph node metastasis in patients with Wilms' tumor. In addition, CRNDE might accelerate the progression of Wilms' tumor via modulating microRNA-424.

The left ventricular assist effect and biocompatibility study of a novel para-aortic counterpulsation device.

OBJECTIVE: To evaluate the hemodynamic characteristics and biocompatibility of a new para-aortic counterpulsation device in animal experiment studies. MATERIALS AND METHODS: Para-aortic counterpulsation device (PACD), a monoport device, consists of a blood chamber anastomosed to the descending aorta by means of a valveless graft and an air chamber connected to IABP machine. Hemodynamic parameters during the PACD-assisted beats were compared with those during the unassist beats. Acute heart failure was induced in all animals, and the hemodynamic effects of PACD were then reassessed. RESULTS: We successfully induced heart failure in all cases, in conditions of which cardiac output (CO) and MAP decreased 17.6% and 27.7% respectively, and PCWP increased 57.7%. Hemodynamic indexes, cerebral and heart perfusion improved significantly after PACD assisting. PACD activation increased significantly CO and MAP 6.29% and 2.04% respectively. Both of SAP and DAP decreased significantly from 85.00 to 81.88 mmHg and 59.63 to 54.63 respectively, at the same time, MADP increased 19.4%, after PACD assist. The value of MDLMF, LMF and CSF was increased by 14.0%, 13.8% and 11.6% respectively. LCAF increased by 11.23%, after PACD assist. The PFH increased significantly in the first six hours. There was no statistically significant difference in the last two hours. When the acute animal experiments were completed, there were no infarct ischemic, thrombosis change in organs by Gross and histologic observation. CONCLUSIONS: PACD with good biological compatibility significantly reduced the left ventricular afterload, increased diastolic arterial pressure and myocardial perfusion, improved heart function and cerebral perfusion.

Over-expression of the Arabidopsis CBF1 gene improves resistance of tomato leaves to low temperature under low irradiance.

A known Arabidopsis cDNA clone, the CRT/DRE binding factor 1 (CBF1), was isolated and introduced into tomato plants. CBF1 is a member of the CBF gene family related to low temperature and enhanced low temperature tolerance in plants. In the present work, transcripts of CBF1 could be detected in transgenic tomato leaves, and the photochemical efficiency of PSII (F(v) /F(m)) and oxidisable P700 in the transgenic tomato over-expressing CBF1 were higher than in non-transformed plants under low temperature stress at low irradiance. Similarly, higher activity of superoxide dismutase (SOD), higher non-photochemical quenching (NPQ), and lower malondialdehyde (MDA) content were also detected in transgenic tomato leaves. These results suggest that CBF1 protein plays an important role in protection of PSII and PSI during low temperature stress at low irradiance.

The neurofibromatosis type 2 gene product, merlin, reverses the F-actin cytoskeletal defects in primary human Schwannoma cells.

Schwannoma tumors, which occur sporadically and in patients with neurofibromatosis, account for 8% of intracranial tumors and can only be treated by surgical removal. Most schwannomas have biallelic mutations in the NF2 tumor suppressor gene. We previously showed that schwannoma-derived Schwann cells exhibit membrane ruffling and aberrant cell spreading when plated onto laminin, indicative of fundamental F-actin cytoskeletal defects. Here we expand these observations to a large group of sporadic and NF2-related tumors and extend them to schwannomatosis-derived tumors. Mutation at NF2 correlated with F-actin abnormalities, but the extent of morphological change did not correlate with the type of NF2 mutation. We used a recently described molecular strategy, TAT-mediated protein transfer, to acutely introduce the NF2 protein, merlin, into primary human schwannoma cells in an attempt to reverse the cytoskeletal phenotype. Abnormal ruffling and cell spreading by cells with identified NF2 mutations were rapidly reversed by introduction of TAT-merlin. The effect is specific to TAT-merlin isoform 1, the growth-suppressive isoform of merlin. TAT-merlin isoform 2, a TAT-merlin mutant (L64P), and merlin lacking TAT were ineffective in reversing the cytoskeletal phenotype. Results show that merlin isoform 1 is sufficient to restore normal actin organization in NF2-deficient human tumor cells, demonstrating a key role for merlin in the NF2 phenotype. These results lay the foundation for epigenetic complementation studies in NF2 mouse models and possibly for experiments to evaluate the utility of merlin transduction into patients as protein therapy.

Interaction between two isoforms of the NF2 tumor suppressor protein, merlin, and between merlin and ezrin, suggests modulation of ERM proteins by merlin.

The product of the neurofibromatosis type II (NF2) tumor suppressor gene, merlin, is closely related to the ezrin-radixin-moesin (ERM) family, a group of proteins believed to link the cytoskeleton to the plasma membrane. Mutation in the NF2 locus is associated with Schwann cell tumors (schwannomas). The two predominant merlin isoforms, I and II, differ only in the carboxy-terminal 16 residues and only isoform I is anti-proliferative. Merlin lacks an actin-binding domain conserved among ezrin, radixin and moesin. Because merlin, ezrin and moesin are co-expressed in Schwann cells, and all homodimerize, we have examined whether merlin and ezrin dimerize with one another. We found by immunoprecipitation and yeast two-hybrid assays that both merlin isoforms interact with ezrin. The interaction occurs in a head-to-tail orientation, with the amino-terminal half of one protein interacting with the carboxy-terminal half of the other. The two merlin isoforms behave differently in their interaction with ezrin. Isoform I binds only ezrin whose carboxy-terminus is exposed, whereas isoform II binds ezrin regardless of whether ezrin is in the open or closed conformation. The heterodimerization of merlin is a much stronger interaction than the interaction between either merlin isoform and ezrin, and can inhibit merlin-ezrin binding. This suggests that, in vivo, merlin dimerization could regulate merlin-ERM protein interaction, and could thus indirectly regulate other interactions involving ERM proteins.

Two-hybrid analysis reveals fundamental differences in direct interactions between desmoplakin and cell type-specific intermediate filaments.

Desmosomes are cell junctions that act as sites of strong intercellular adhesion and also serve to anchor the intermediate filament (IF) cytoskeleton to the plasma membrane of a variety of cell types. Previous studies demonstrated that the COOH terminus of the desmosomal plaque protein, desmoplakin (DP), is required for the association of DP with IF networks in cultured cells and that this domain interacts directly with type II epidermal keratin polypeptides in vitro. However, these studies left open the question of how desmosomes might anchor other IF types known to associate with these junctions. In this report we used yeast two-hybrid and in vitro dot blot assays to further examine the requirements for direct interactions between desmoplakin and various IF types. Our results confirm the ability of the DP COOH terminus (DPCT) to interact with at least two regions of the head domain of the type II epidermal keratin K1 and also demonstrate that DPCT can interact with the type III IF family members, vimentin and desmin, as well as simple epithelial keratins. Unlike the situation for type II epidermal keratins, the interaction between DPCT and simple epithelial keratins appears to depend on heterodimerization of the type I and II keratin polypeptides, since both are required to detect an interaction. Furthermore, although the interaction between DPCT and K1 requires the keratin head domain, deletion of this domain from the simple epithelial keratins does not compromise interaction with DPCT. The interaction between DPCT and type III or simple epithelial keratins also appeared to be less robust than that between DPCT and K1. In the case of K8/K18, however, the interaction as assessed by yeast two-hybrid assays increased 9-fold when a serine located in a protein kinase A consensus phosphorylation site 23 residues from the end of DP was altered to a glycine. Taken together, these data indicate that DP interacts directly with different IF types in specific ways.

Intermediate filament protein domain interactions as revealed by two-hybrid screens.

All intermediate filament proteins possess three distinct domains: heads, rod and tail, and subdomains within the rod called helices 1A, 1B, 2A, and 2B. Subunit packing within a filament is a consequence of interactions among these domains. Several such interactions are known, but probably many more contribute to stabilizing filament structure. We examined a number of such potential interactions using the yeast two-hybrid system. Domains or subdomains of murine vimentin, a Type III intermediate filament protein, were fused with either the DNA-binding or trans-activating domain of GAL4, a transcription factor. Interaction between the vimentin domains/subdomains functionally reconstituted GAL4, thereby activating transcription of a GAL1-LacZ reporter gene. The oligomeric state at which the interactions took place, i.e. whether the domains/subdomains were dimeric or tetrameric as they interacted, was also determined. These studies revealed a number of interesting interactions, among which was a strong homotypic binding to helix 2B to form tetramers. They also demonstrated a lack of interaction among others expected to do so based on current structural models. From these results we deduced which of the candidates for interactions, suggested by current models, were true protein-protein interactions and which represented nearest-neighbors only. Thus, the A11 and A22 modes of molecular alignment identified by Steinert et al. (Steinert, P. M., Marekov, L. N., Fraser, R. D. B., and Parry, D. A. D. (1993) J. Mol. Biol. 230, 436-452) are probably true interactions, whereas the A12 and ACN modes may describe adjacent but non-interacting molecules.

Charge interactions in the rod domain drive formation of tetramers during intermediate filament assembly.

The purpose of this study was to test a long standing hypothesis regarding the forces that drive the assembly of intermediate filaments (IFs). The initial step of IF assembly is the formation of dimeric, alpha-helical coiled coils. On the outside of the coiled coils, charged amino acids are distributed periodically such that positively and negatively charged residues are arranged in alternating zones, 9.5/2 residues wide (Parry et al., 1977; McLachlan and Stewart, 1982). This structural feature has given rise to the hypothesis that, if neighboring coiled coils were staggered axially by an odd multiple of a charged zone, electrostatic interactions between them could provide the driving force for the assembly of higher order oligomers or filaments (Fraser et al., 1986; Parry and Steinert, 1992). Using the IF protein vimentin as a model system, we carried out deletion mutagenesis experiments to test this hypothesis. We generated mutant vimentin proteins lacking 14, 21, and 28 residues in Helix 1B of the rod domain, and analyzed their assembly properties by DNA transfection into IF null cells, in vitro assembly, and chemical cross-linking. Results from these experiments are consistent with, and support, the hypothesis that charge complementation plays a key role in the assembly and stabilization of intermediate filaments.