[The value of CMR high-risk attributes in predicting ventricular remodeling in ST-segment-elevation myocardial infarction patients with mildly reduced or preserved ejection fraction].

Objective: To evaluate the predictive value of a multiparametric cardiac magnetic resonance (CMR) approach for ventricular remodeling in ST-segment-elevation myocardial infarction (STEMI) patients with mildly reduced or preserved left ventricular ejection fraction (LVEF). Methods: This study is a prospective cohort study. STEMI patients with acute LVEF>40% after primary percutaneous coronary intervention (PCI) in Beijing Anzhen Hospital from October 2019 to September 2021 were enrolled. All patients received acute (3-7 days) and follow-up (3 months) CMR post-PCI. According to absence or presence of ventricular remodeling, patients were divided into ventricular remodeling group and non-ventricular remodeling group. Basic clinical characteristics and CMR indicators were analyzed and compared between the two groups. Logistic regression and receiver operating characteristic (ROC) curves were used to explore the predictive performance of CMR high-risk attributes for ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The predictive value of combining multiple high-risk characteristics of CMR for ventricular remodeling was analyzed and compared with the traditional clinical risk factor model. Results: A total of 123 STEMI patients were enrolled (aged (57.1±11.1) years, 102 (82.9%) males). There were 97 cases (78.9%) patients in the non-ventricular remodeling group and 26 cases (21.1%) in the ventricular remodeling group. After adjustment for clinical risk factors, stroke volume<51.6 ml, global circumferential strain>-13.7%, infarct size>39.2%, microvascular obstruction>0.5%, and myocardial salvage index<43.9 were independently associated with ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The incidence of ventricular remodeling increased with the increasing number of CMR high-risk attributes (P<0.01). The number of CMR high-risk attributes ≥3 was an independent predictor of adverse remodeling (adjusted OR=5.95, 95 CI%: 2.25-15.72, P<0.01) in STEMI patients with mildly reduced or preserved LVEF. Furthermore, the number of CMR high-risk attributes had incremental predictive value over baseline clinical risk factors (area under curve: 0.843 vs. 0.696, P<0.01). Conclusions: In STEMI patients with mild reduced or preserved LVEF, 5 CMR characteristics are associated with ventricular remodeling. The combination of ≥3 CMR high-risk characteristics is an independent predictor of ventricular remodeling, which has incremental predictive value beyond traditional risk factors in this patient cohort.

The effect of pre-hospital statins therapy on incidence of in-hospital death and total MACCE in patients with PCI.

OBJECTIVE: To investigate the influence of preoperative statin therapy on rate of major adverse cardiac and cerebrovascular events (MACCE) during hospital stay after successful percutaneous coronary intervention (PCI). METHODS: Review of patients who underwent PCI between June 2003 and September 2005 (n = 3893) at Beijing Anzhen Hospital of Capital University of Medical Science. (Group I, on statins, n = 3361; group II, not on statins, n = 532). To investigate if preoperative statin therapy was independently associated with the reduction in the risk of adverse postoperative outcomes after PCI. Prognostic factors were assessed using Cox multivariate regression analysis to determine if preoperative statin therapy was independently associated with a reduction in the risk of adverse postoperative outcomes. RESULTS: Our study demonstrated that preoperative statin therapy was not associated with a reduction in risk of mortality and overall MACCE during the hospital stay (0.3% vs. 0.4%; 1.4% vs. 1.2%P > 0.05, respectively).Compared with patients not receiving statins therapy, the hazard ratio for mortality in hospital was 0.738 (95% CI, 0.499-1.211, P = 0.229). CONCLUSIONS: Preoperative statin therapy did not reduce the risk of mortality and the rates of MACCE during the hospital stay after successful PCI. Cox multivariate regression analysis showed that independent prognostic parameters for mortality were Age, LVEF<50%, Triple vessel CAD, and DM (diabetes mellitus).

Characterization of a cDNA coding for sex steroid-binding protein of human plasma.

A cDNA (912 nucleotides) coding for human plasma sex steroid-binding protein (SBP) was characterized from a phage clone previously isolated by screening a Charon 21A human liver cDNA library with rat androgen binding protein (ABP) cDNA. The deduced amino acid sequence from the cDNA indicated that the insert was a partial clone coding for 281 amino acids starting with residue 92 (glycine) encompassing the alternating leucyl residues and the carboxyl-end 373 (histidine) as previously reported [(1986) Biochemistry 25, 7584]. The potential polyadenylation signal sequence ATTAAA is present as part of the 3'-coding region and the stop codon TAA. Both are followed by a short 20 untranslated nucleotides and a poly(A) tract of 49 nucleotides. Significant homologous sequences (76%) at the DNA level exist between human SBP and rat ABP which might suggest the possibility that both evolved from a common primordial gene. Demonstration of the presence of an SBP cDNA in a human liver cDNA library provides the first evidence that liver is the site of SBP biosynthesis.

Cloning of fibrinogen genes and their cDNA.

Cross-species hybridizations have enabled us to isolate and clone the gene for the beta chain of human fibrinogen. Highlights of the gene for the beta chain revealed by nucleotide sequence analyses, particularly in areas that have a direct bearing on defining the overall organization of the gene, have been presented. Nucleotide sequence determination has confirmed the presence of seven intervening sequences. The positions where several of these intervening sequences interrupt the coding region appear to be related to the functional domains of the polypeptide. A putative signal peptide has been identified. Studies on the cDNA for the human alpha chain indicate that the alpha chain polypeptide may be synthesized in a precursor form with a COOH-terminal extension of 15 amino acids as compared to the alpha chain present in the mature molecule found in plasma. We are in the process of isolating the genes for the alpha and gamma chains by a similar approach. We are hopeful that these studies will provide information as to how they are regulated and how they have undergone changes in the course of evolution.

Synthesis and secretion of MCP-1 by dental follicle cells--implications for tooth eruption.

The monocyte chemotactic protein-1 (MCP-1) gene is expressed in the dental follicle, a loose connective tissue sac that must be present for eruption to occur. The role of MCP-1 may be to recruit mononuclear cells (monocytes) to the dental follicle, where these cells, in turn, fuse to form osteoclasts to resorb alveolar bone for the formation of an eruption pathway. Thus, it was the aim of this study to determine if MCP-1 is secreted by dental follicle cells in culture and if its secretion is enhanced by potential tooth eruption molecules. Western blotting and a two-site capture enzyme-linked immunoabsorbent assay demonstrated that MCP-1 was synthesized and secreted into the medium by the follicle cells. Incubation of the cells with either transforming growth factor-beta one (TGF-beta 1) or interleukin-one alpha (IL-1 alpha) enhanced the secretion of MCP-1 by the cells. Measurement of the chemotactic ability of the conditioned medium to attract mouse monocytes demonstrated that the chemotaxis of the medium was increased if the cells had previously been incubated in IL-1 alpha, although there appears to be a threshold concentration of MCP-1 above which chemotaxis is not enhanced. These combined results suggest that the critical initial cellular event of tooth eruption, an influx of mononuclear cells into the dental follicle at an early post-natal age, may be initiated by the secretion of MCP-1 by the dental follicle cells.

Colony-stimulating factor-1 and monocyte chemotactic protein-1 chemotaxis for monocytes in the rat dental follicle.

Tooth eruption requires the influx of mononuclear cells (monocytes) into the dental follicle to form osteoclasts that resorb the alveolar bone to form an eruption pathway. Candidate molecules to attract these monocytes are colony-stimulating factor-1 (CSF-1) which is produced in the dental follicle, and monocyte chemotactic protein-1 (MCP-1), which is known to be a chemoattractant for monocytes. Using reverse transcription-polymerase chain reaction techniques, it was shown that the follicle cells of the first mandibular molar of the rat transcribe MCP-1 with maximal expression in vivo at day 3 postnatally, the time of peak expression of CSF-1 as well. This is also the day of peak influx of monocytes into the follicle. To determine if these molecules that were produced by the dental follicle were chemotactic, a chemotactic assay using a mouse monocyte cell line was conducted. CSF-1 or MCP-1 alone were found to be chemotactic for the monocytes and conditioned medium from the cultured follicle cells also was chemotactic. Incubating the conditioned medium with antibodies against either CSF-1 or MCP-1 reduced the chemotaxis. The results demonstrate that both CSF-1 and MCP-1 produced by the dental follicle are chemotactic for monocytes and that these chemoattractants might be responsible for the influx of monocytes into the follicle necessary to initiate tooth eruption.

Enhancement of gene expression in rat dental follicle cells by parathyroid hormone-related protein.

Recent studies indicate that parathyroid hormone-related protein (PTHrP) is required for tooth eruption in mice. Localized in the stellate reticulum, PTHrP might exert a paracrine effect on cells of the adjacent dental follicle to initiate eruption. The presence of a follicle is needed for eruption and, at the cellular level, there is an influx of mononuclear cells in the follicle early postnatally in the first mandibular molar of the rat. In turn, these mononuclear cells fuse to form osteoclasts, which erode the alveolar bone to form an eruption pathway. At the molecular level, the dental follicle cells of the rat molar maximally express the genes for monocyte chemotactic protein-1 (MCP-1) and colony-stimulating factor-1 (CSF-1) at day 3 postnatally. Because day 3 also is the time of maximal influx of the mononuclear cells into the follicle, MCP-1 and CSF-1 could be involved in the recruitment/maturation of these cells. To determine if PTHrP can modulate gene expression in the dental follicle, cultured follicle cells were immunostained to show the receptor for PTHrP. The gene expression of this receptor was enhanced by incubating the cells with interleukin-1alpha (IL-1alpha). Next, the ability of PTHrP itself to enhance gene expression of either MCP-1 or CSF-1 in the dental follicle cells was determined by incubating the cells with PTHrP in either a time- or concentration-course manner (1-15 h or 1-100 ng/ml). By reverse transcription-polymerase chain reaction, it was demonstrated that PTHrP enhanced MCP-1 expression in a concentration-dependent fashion, with 50 ng PTHrP/ml inducing maximal expression of either MCP-1 or CSF-1. In the time-dependent studies, PTHrP caused maximal expression within 30 min for either MCP-1 or CSF-1. Immunoblotting revealed that PTHrP also enhanced secretion of MCP-1 by the follicle cells. Thus, one of the actions of PTHrP in tooth eruption may be that it enhances MCP-1 and CSF-1 gene expression and secretion in the dental follicle. Moreover, IL-1alpha may accentuate its action by enhancing the expression for the PTHrP receptor in the follicle cells.

Implications for tooth eruption of the effect of interleukin-1alpha on nuclear factor-kappaB gene expression in the rat dental follicle.

Tooth eruption is a localized event and a cascade of molecular signals generated in the dental follicle and stellate reticulum appears to initiate its onset. Consequently, mononuclear cells are recruited into the follicle and, in turn, fuse to become osteoclasts needed to resorb the alveolar bone to form an eruption pathway. One of the transcription factors involved in the sequence of molecular signalling may be nuclear factor (NF)kappaB. This study shows that NFkappaB is expressed and synthesized by cultured dental follicle cells. Moreover, its transcription, activation and translocation were enhanced by interleukin (IL)-1alpha, a potential eruption molecule. The enhancement of transcription of the NFkappaB gene by IL-1alpha was blocked by a tyrosine-specific kinase inhibitor, suggesting that the enhancement may require the phosphorylation of the NFkappaB complex. In vivo, NFkappaB is maximally expressed in the dental follicle of the rat first mandibular molar at day 3 postnatally, the age at which there is a peak influx of mononuclear cells into the follicle. Thus, a transcription factor apparently required for eruption (NFkappaB) is present in the tissue required for eruption, the dental follicle, and its gene expression is maximal at a critical time in eruption.

Tooth eruption molecules enhance MCP-1 gene expression in the dental follicle of the rat.

Tooth eruption is a localized developmental event that requires the presence of the dental follicle, a loose connective tissue sac that surrounds each tooth. Early postnatally in the first mandibular molar of the rat there is an influx into the follicle of mononuclear cells (monocytes) which, in turn, fuse to form osteoclasts that resorb the bone to form an eruption pathway. The chemoattractant that may attract the mononuclear cells to the follicle to initiate the cellular events of eruption is monocyte chemotactic protein-one (MCP-1). MCP-1 is secreted by the dental follicle cells and its gene is expressed maximally at an early postnatal age, correlating with the monocyte influx into the follicle. In this study, we show that other potential tooth eruption molecules--EGF, IL-1alpha, TGF-beta1 and CSF-1--all enhance the expression of the MCP-1 gene in the cultured dental follicle cells. In vivo, injections of IL-1alpha or EGF also enhance the gene expression of MCP-1 in the follicle with maximal enhancement occurring in the early postnatal days. Thus, there appears to be a redundant function of the different tooth eruption genes to ensure that the MCP-1 gene is expressed. In turn, expression of MCP-1 may be critical for recruiting the monocytes to the dental follicle to initiate the cellular events of tooth eruption.

Isolation and analysis of a cDNA coding for human C1 inhibitor.

A cDNA coding for C1 inhibitor was isolated from a human liver lambda gt11 expression library and sequenced by the dideoxy method. The amino acid sequence deduced from the cDNA indicated that the insert was a partial clone coding for 310 amino acids including the reactive site present at the carboxyl end of the molecule. The reactive site corresponds to that previously reported by Salvesen et al. (J. Biol. Chem. 260, 2432, 1985). The cDNA also contained a stop codon of TGA, 264 nucleotides at the 3' noncoding region, and a polyadenylation signal sequence of AATAAA 15 nucleotides upstream from the poly(A) tail. The amino acid sequence flanking the reactive site of the inhibitor is homologous to other members of the superfamily of plasma serine protease inhibitors.

Characterization of a cDNA coding for human factor XII (Hageman factor).

Affinity-purified antibody against human factor XII (Hageman factor) has been radiolabeled with 125I and employed as a probe to screen a human liver cDNA expression library prepared in lambda gt11. Approximately 3.5 X 10(6) recombinant phages were screened for factor XII, and two positive clones were identified and plaque purified. The largest cDNA coding for factor XII was 1571 base pairs in length and coded for amino acid residues 127-596 in the mature protein, a termination codon of TGA, a 3' noncoding sequence of 147 nucleotides, and a poly(A) tail of 11 nucleotides. The second clone contained an insert of 1334 base pairs and coded for amino acid residues 200-596. The amino acid sequence predicted by the cDNAs was in excellent agreement with that previously determined by amino acid sequence analysis. The amino acid and DNA sequences in human factor XII showed considerable homology with the corresponding domains in other serine proteases, including prothrombin, plasminogen, tissue plasminogen activator, and urokinase.

Copper-induced tissue factor expression in human monocytic THP-1 cells and its inhibition by antioxidants.

BACKGROUND: Transition metals such as copper are known to initiate free radical formation and lipid peroxidation. Recent reports suggest that intracellular reactive oxygen intermediates can induce the transcription of a number of important genes. The present study examines the effects of copper and iron on the ability of monocytic cells to synthesize and express tissue factor, the potent procoagulant factor. METHODS AND RESULTS: Exposure of human monocytic THP-1 cells to 5 to 10 mumol/L Cu2+ led to cell damage and the expression of tissue factor activity to levels up to 70 times higher than control, as measured by a single-stage plasma coagulation assay. These effects were seen only in the presence of a lipophilic chelating agent, 8-hydroxyquinoline, suggesting that intracellular transport of Cu2+ was required. The effects of Cu2+ were mimicked by ceruloplasmin but not by Fe3+ or hemin. The induction of tissue factor activity by Cu2+ was slow in onset (6 hours) but sustained (24 hours) and was accompanied by increased tissue factor mRNA levels, measured by reverse transcription/polymerase chain reaction after annealing with oligomer primers. Increases in tissue factor protein, measured by a specific immunoassay, also occurred but were smaller than those in activity. Cu2+, therefore, appears to act at both the transcriptional and posttranslational levels. The effects of Cu2+ were inhibited by a number of lipophilic antioxidants, including probucol, vitamin E, butylated hydroxytoluene, and a 21-aminosteroid, U74389G. CONCLUSIONS: Exposure of monocytes to oxidizing conditions may lead to the expression of high levels of tissue factor activity, with accompanying risk for disseminated intravascular coagulation, and this may be inhibited by lipophilic antioxidants.

Degradation of deoxyribonucleic acid by a 1,10-phenanthroline-copper complex: the role of hydroxyl radicals.

Degradation of deoxyribonucleic acid (DNA) by 1,10-phenanthroline has been shown to require Cu(II), a reducing agent, and O2. Other metal ions do not substitute for Cu(II), and degradation of DNA is inhibited by metal ions that can form stable complexes with 1,10-phenanthroline, such as Co(II), Cd(II), Ni(II), or Zn(II), as well as by chelators that can bind copper, such as triethyltetraamine, neocuproine, or ethylenediaminetetraacetic acid (EDTA). Neocuproine, a specific copper chelator, is more effective than EDTA in inhibiting the breakdown of DNA. The degradation of DNA shows a requirement for a reducing agent which can be satisfied by either ascorbate or a thiol. A free radical generating system, e.g., xanthine oxidase-hypoxanthine, can substitute for the reducing agent. DNA degradation, in the presence of either an organic reducing agent or xanthine oxidase-hypoxanthine, is inhibited by hydroxyl radical scavengers and by catalase, suggesting that hydroxyl radical is the reactive species in DNA degradation and that hydrogen peroxide is an intermediate in hydroxyl radical generation.

Mechanisms of selective inhibition of 3' to 5' exonuclease activity of Escherichia coli DNA polymerase I by nucleoside 5'-monophosphates.

The 3' to 5' exonuclease activity of Escherichia coli DNA polymerase I can be selectively inhibited by nucleoside 5'-monophosphates, wherease the DNA polymerase activity is not inhibited. The results of kinetic studies show that nucleotides containing a free 3'-hydroxy group and a 5'-phosphoryl group are competitive inhibitors of the 3' to 5' exonuclease. Previous studies by Huberman and Kornberg [Huberman, J., and Kornberg, A. (1970), J. Biol. Chem. 245, 5326] have demonstrated a binding site for nucleoside 5'-monophosphates on DNA polymerase I. The Kdissoc values for nucleoside 5'-monophosphates determined in that study are comparable to the Ki values determined in the present study, suggesting that the specific binding site for nucleoside 5'-monophosphates represents the inhibitor site of the 3' to 5' exonuclease activity. We propose that (1) the binding site for nucleoside 5'-monophosphates on DNA polymerase I may represent the product site of the 3' to 5' exonuclease activity. (2) the primer terminus site for the 3' to 5' exonuclease activity is distinct from the primer terminus site for the polymerase activity, and (3) nucleoside 5'-monophosphates bind at the primer terminus site for the 3' to 5' exonuclease activity.

Gene expression of potential tooth eruption molecules in the dental follicle of the mouse.

Tooth eruption requires alveolar bone resorption and the presence of the dental follicle, a loose connective tissue sac that surrounds each tooth. This bone resorption involves the follicle in that mononuclear cells enter the follicle to form osteoclasts which resorb bone to form the eruption pathway. In the rat first mandibular molar, probable eruption genes, CSF-1, c-fos, NFkappaB and MCP-1, are expressed maximally in the dental follicle at day 3 postnatally. This correlates with the time of peak influx of mononuclear cells into the follicle. In the mouse, the first peak influx of mononuclear cells into the first mandibular molar is at day 5 postnatally, and this study demonstrates that all four of the above resorption molecules are maximally expressed at this time in the dental follicle. Thus, this work suggests that these molecules may play a role in the cellular events of eruption (mononuclear cell influx and osteoclast formation) in the mouse molar at day 5 postnatally just as they do at day 3 in the rat molar. These results provide a standard for future studies on eruption in the mouse molar and extends the number of species in which putative eruption molecules are expressed at a critical time of eruption.

K+ channel blockers inhibit tissue factor expression by human monocytic cells.

Human monocytes express the important procoagulant protein, tissue factor (TF), after stimulation by a variety of agents, including bacterial lipopolysaccharide (LPS). Monocyte TF expression may contribute to intravascular coagulation in a number of disease states. The present studies show that monocytic cell TF expression can be inhibited by several agents known to block cellular K+ channels. Exposure of human peripheral blood to 100 ng/mL LPS for 2 hours led to pronounced TF procoagulant activity associated with the mononuclear cell fraction. This was inhibited by 4-aminopyridine (2 mmol/L), tetraethylammonium chloride (10 mmol/L), and apamin (1 mumol/L). In contrast, charybdotoxin (100 nmol/L) was inactive. More detailed studies were carried out in cultured human monocytic tumor THP-1 cells. These cells exhibited low but detectable levels of TF mRNA, measured by reverse transcription and polymerase chain reaction; cell surface procoagulant activity, measured by a plasma clotting assay; and cell homogenate TF antigen, measured by immunoassay. Exposure of THP-1 cells to 1 microgram/mL LPS led to threefold to fivefold increases in all three parameters. Basal and LPS-induced levels of all three parameters were reduced in a dose-dependent manner by 4-aminopyridine (I50, 1 mmol/L) and tetraethylammonium chloride (I50, 20 mmol/L) but not by apamin or charybdotoxin. Expression of TF activity was also inhibited by glibenclamide, an inhibitor of ATP-dependent K+ channels (I50, 25 mumol/L). These results suggest that facilitation of TF synthesis may be an important role for K+ channels in monocytes.

Effects of prostacyclin analogs on the synthesis of tissue factor, tumor necrosis factor-alpha and interleukin-1 beta in human monocytic THP-1 cells.

Previous studies have shown that prostacyclin analogs can inhibit the expression of tissue factor (TF) procoagulant activity by human monocytes. The present studies have investigated this phenomenon further, by using a plasma coagulation assay to measure cellular TF activity, an immunoassay to measure TF antigen and reverse transcription/polymerase chain reaction with appropriate oligomer primers to measure TF mRNA. Iloprost and cicaprost inhibited lipopolysaccharide-induced increases in TF activity, antigen and mRNA (50% inhibition, 2-8 nM), with no apparent effect on TF mRNA stability. These agents therefore act at or before the level of transcription of the TF gene. The analogs were more potent inhibitors of tumor necrosis factor-alpha synthesis (50% inhibition at 334 +/- 40 pM cicaprost or 846 +/- 182 pM iloprost) and extraordinarily potent when combined with a phosphodiesterase inhibitor (50% inhibition at 101 +/- 31 pM iloprost in the presence of 20 microM isobutylmethylxanthine). Iloprost and cicaprost were less potent in inhibiting the synthesis of interleukin-1 beta (50% inhibition, 50-100 nM). Cicaprost inhibited lipopolysaccharide-induced increases in mRNA levels for TF, tumor necrosis factor-alpha and interleukin-1 beta; differential potency was again observed. We conclude that these three important monocyte functions can be down-regulated by prostacyclin analogs, and with differential sensitivity. Furthermore, the extreme sensitivity of tumor necrosis factor-alpha synthesis to inhibition suggests that such inhibition may be a major physiological function of prostacyclin itself.

Characterization of complementary deoxyribonucleic acid and genomic deoxyribonucleic acid for the beta chain of human fibrinogen.

A total of 148 cDNAs coding for the beta chain of human fibrinogen have been identified from a human liver cDNA library employing a bovine cDNA as a probe. The largest cDNA insert contained 1932 base pairs cloned into the PstI site of plasmid pBR322. This cDNA insert contained 66 base pairs coding for a portion or all of a signal sequence, 1383 base pairs coding for 461 amino acids in the mature protein, a stop codon of TAG, a noncoding region of 431 base pairs, and a poly(A) tail of 19 base pairs. Most of the cDNA inserts coding for the beta chain were found to have a noncoding region of 98 or 167 base pairs rather than 431 base pairs at the 3'-end. The bovine cDNA for the beta chain was also employed as a probe for screening a lambda phage library containing human genomic DNA. Seven positive phage were identified. One of the phage, which contained the entire gene for the beta chain of fibrinogen, was examined by electron microscopy, and portions of its DNA sequence are presented. Seven intervening sequences were identified in the gene for the beta chain of human fibrinogen. The largest intervening sequence (approximately 1.3 kilobases) was found at the 5'-end of the gene and was located between amino acid residues 8 and 9, which are present in fibrinopeptide B. A sequence analysis of the 5'-end of the gene also indicated that the B chain of human fibrinogen contained a signal sequence of either 16, 27, or 30 amino acid residues.