Acute pericardial postischemic inflammatory responses: Characterization using a preclinical porcine model.

BACKGROUND: Pericardial fluid (PF) contains cells, proteins, and inflammatory mediators, such as cytokines, chemokines, growth factors, and matrix metalloproteinases. To date, we lack an adequate understanding of the inflammatory response that acute injury elicits in the pericardial space. OBJECTIVE: To characterize the inflammatory profile in the pericardial space acutely after ischemia/reperfusion. METHODS: Pigs were used to establish a percutaneous ischemia/reperfusion injury model. PF was removed from pigs at different time points postanesthesia or postischemia/reperfusion. Flow cytometry was used to characterize the immune cell composition of PF, while multiplex analysis was performed on the acellular portion of PF to determine the concentration of inflammatory mediators. There was a minimum of 3 pigs per group. RESULTS: While native PF mainly comprises macrophages, we show that neutrophils are the predominant inflammatory cell type in the pericardial space after injury. The combination of acute ischemia/reperfusion (IR) and repeatedly accessing the pericardial space significantly increases the concentration of interleukin-1 beta (IL-1ß) and interleukin-1 receptor antagonist (IL-1ra). IR significantly increases the pericardial concentration of TGFß1 but not TGFß2. We observed that repeated manipulation of the pericardial space can also drive a robust pro-inflammatory response, resulting in a significant increase in immune cells and the accumulation of potent inflammatory mediators in the pericardial space. CONCLUSION: In the present study, we show that both IR and surgical manipulation can drive robust inflammatory processes in the pericardial space, consisting of an increase in inflammatory cytokines and alteration in the number and composition of immune cells.

Pericardial Fluid Accumulates microRNAs That Regulate Heart Fibrosis after Myocardial Infarction.

Pericardial fluid (PF) has been suggested as a reservoir of molecular targets that can be modulated for efficient repair after myocardial infarction (MI). Here, we set out to address the content of this biofluid after MI, namely in terms of microRNAs (miRs) that are important modulators of the cardiac pathological response. PF was collected during coronary artery bypass grafting (CABG) from two MI cohorts, patients with non-ST-segment elevation MI (NSTEMI) and patients with ST-segment elevation MI (STEMI), and a control group composed of patients with stable angina and without previous history of MI. The PF miR content was analyzed by small RNA sequencing, and its biological effect was assessed on human cardiac fibroblasts. PF accumulates fibrotic and inflammatory molecules in STEMI patients, namely causing the soluble suppression of tumorigenicity 2 (ST-2), which inversely correlates with the left ventricle ejection fraction. Although the PF of the three patient groups induce similar levels of fibroblast-to-myofibroblast activation in vitro, RNA sequencing revealed that PF from STEMI patients is particularly enriched not only in pro-fibrotic miRs but also anti-fibrotic miRs. Among those, miR-22-3p was herein found to inhibit TGF-ß-induced human cardiac fibroblast activation in vitro. PF constitutes an attractive source for screening diagnostic/prognostic miRs and for unveiling novel therapeutic targets in cardiac fibrosis.

A Carrier-Based Quantitative Proteomics Method Applied to Biomarker Discovery in Pericardial Fluid.

Data-dependent liquid chromatography tandem mass spectrometry is challenged by the large concentration range of proteins in plasma and related fluids. We adapted the SCoPE method from single-cell proteomics to pericardial fluid, where a myocardial tissue carrier was used to aid protein quantification. The carrier proteome and patient samples were labeled with distinct isobaric labels, which allowed separate quantification. Undepleted pericardial fluid from patients with type 2 diabetes mellitus and/or heart failure undergoing heart surgery was analyzed with either a traditional liquid chromatography tandem mass spectrometry method or with the carrier proteome. In total, 1398 proteins were quantified with a carrier, compared to 265 without, and a higher proportion of these proteins were of myocardial origin. The number of differentially expressed proteins also increased nearly four-fold. For patients with both heart failure and type 2 diabetes mellitus, pathway analysis of upregulated proteins demonstrated the enrichment of immune activation, blood coagulation, and stress pathways. Overall, our work demonstrates the applicability of a carrier for enhanced protein quantification in challenging biological matrices such as pericardial fluid, with potential applications for biomarker discovery. Mass spectrometry data are available via ProteomeXchange with identifier PXD053450.

Pericardial fluid troponin in cardiac surgery.

BACKGROUND AND OBJECTIVE: Pericardial Fluid (PF) is a rich reservoir of biologically active factors. Due to its proximity to the heart, the biochemical structure of PF may reflect the pathological changes in the cardiac interstitial environment. This manuscript aimed to determine whether the PF level of cardiac troponins changes in patients undergoing cardiac surgery. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar databases were electronically searched for primary studies using the keywords "pericardial fluid," "troponin," and "cardiac surgery." The primary outcome of interest was changes in troponin levels within the PF preoperatively and postoperatively. Secondary outcomes of interest included comparisons between troponin level changes in the PF compared to plasma. RESULTS: A total of 2901 manuscripts were screened through a title and abstract stage by two independent blinded reviewers. Of those, 2894 studies were excluded, and the remaining seven studies underwent a full-text review. Studies were excluded if they did not provide data or failed to meet inclusion criteria. Ultimately, six articles were included that discussed cardiac troponin levels within the PF in patients who had undergone cardiac surgery. Pericardial troponin concentration increased over time after surgery, and levels were significantly higher in PF compared to serum. All studies found that the type of operation did not affect these overall observations. CONCLUSION: Our review of the literature suggest that the PF level of cardiac troponins increases in patients undergoing cardiac surgery, irrespective of the procedure type. However, these changes' exact pattern and clinical significance remain undefined.

Impact of pericardial fluid glucose level and computed tomography attenuation values on diagnosis of malignancy-related pericardial effusion.

BACKGROUND: We evaluated malignancy according to the characteristics of pericardial fluid in symptomatic Japanese patients undergoing pericardiocentesis and computed tomography (CT). METHODS: This was a retrospective, single-center, observational study of 125 symptomatic patients undergoing pericardiocentesis. The patients were classified into two groups: a malignancy group and a non-malignancy group, according to the primary disease and cytology of the pericardial effusion (PE). We compared the pericardial fluid sample and CT measurements between both groups. RESULTS: All patients were diagnosed as having exudative PE by Light's criteria. PE with malignant cells was demonstrated in 76.8% of the malignancy group patients. Pericardial to serum lactate dehydrogenase (LDH) ratio > 0.6, as one of Light's criteria, was associated with malignancy (p = 0.017). Lower serum brain natriuretic peptide (BNP) concentration was also associated with malignancy (BNP: 126.9 ± 89.8 pg/ml vs 409.2 ± 97.7 pg/ml, malignancy vs non-malignancy groups, respectively; p = 0.037). A significant difference was observed in pericardial fluid glucose level between the malignancy and non-malignancy groups (pericardial fluid glucose: 78.24 ± 48.29 mg/dl vs 98.41 ± 44.85, respectively; p = 0.048). Moreover, CT attenuation values (Hounsfield units (HU)) tended to be higher in the malignancy group vs the non-malignancy group (22.7 [interquartile range (IQR), 17.4-26.0] vs 17.4 [IQR, 13.7-26.4], respectively; p = 0.08). The sensitivity and specificity of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 40.9% and 89.6%, respectively, in the malignancy group. The positive- and negative predictive values of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 85.7% and 50.0%, respectively, in the malignancy group. Pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were cutoff values associated with malignancy (p = 0.012). CONCLUSIONS: Lower pericardial fluid glucose level with higher CT attenuation values may suggest malignancy-related PE.

Local IGF Bioactivity Associates with High PAPP-A Activity in the Pericardial Cavity of Cardiovascular Disease Patients.

OBJECTIVE: Pregnancy-associated plasma protein-A (PAPP-A) has been suggested as a proatherogenic enzyme by its ability to locally increase insulin-like growth factor (IGF) activity through proteolytic cleavage of IGF binding protein-4 (IGFBP-4). Recently, stanniocalcin-2 (STC2) was discovered as an inhibitor of PAPP-A. This study aimed to investigate IGFBP-4, PAPP-A, and STC2 as local regulators of IGF bioactivity in the cardiac microenvironment by comparing levels in the pericardial fluid with those in the circulation of patients with cardiovascular disease. METHODS: Plasma and pericardial fluid were obtained from 39 patients undergoing elective cardiothoracic surgery, hereof 15 patients with type 2 diabetes. Concentrations of IGF-I, intact and fragmented IGFBP-4, PAPP-A, and STC2 were determined by immunoassays and IGF bioactivity by a cell-based assay. RESULTS: In pericardial fluid, the concentrations of total IGF-I, intact IGFBP-4, and STC2 were 72 ± 10%, 91 ± 5%, and 40 ± 24% lower than in plasma, while PAPP-A was 15 times more concentrated. The levels of the 2 IGFBP-4 fragments generated by PAPP-A and reflecting PAPP-A activity were elevated by more than 25%. IGF bioactivity was 62 ± 81% higher in the pericardial fluid than plasma. Moreover, pericardial fluid levels of both IGFBP-4 fragments correlated with the concentration of PAPP-A and with the bioactivity of IGF. All protein levels were similar in pericardial fluid from nondiabetic and diabetic subjects. CONCLUSIONS: PAPP-A increases IGF bioactivity by cleavage of IGFBP-4 in the pericardial cavity of cardiovascular disease patients. This study provides evidence for a distinct local activity of the IGF system, which may promote cardiac dysfunction and coronary atherosclerosis.

Evaluation of the distribution of nicotine intravenous injection: an adult autopsy case report with a review of literature.

We reported the first comprehensive autopsy case of death due to intravenous injection of nicotine. We examined the distribution of nicotine in the body tissues and fluid and exposed the pathophysiology of nicotine poisoning. A 19-year-old woman was rushed to the hospital in cardiorespiratory arrest and was confirmed dead upon arrival. Liquid nicotine, hydrogen peroxide water, and a syringe were found in the hotel room where she stayed. On autopsy, nicotine concentration was the highest (15,023 µg/mg) in the tissue around the injection mark on the right upper arm. Among the body fluids, the intraperitoneal fluid had the highest, whereas the pericardial fluid had the lowest (0.736 µg/mL) nicotine concentration. Among the organs, the brain had the highest (11.637 µg/mg), whereas the fat tissue had the lowest (1.307 µg/mg) nicotine concentration. The concentration of cotinine, which is the metabolite of nicotine, was the highest in the tissue around the injection mark on the right arm (5.495 µg/mg) and was almost the same among the other body fluids and organs. The respective concentrations of nicotine and cotinine were 1.529 µg/mL and 0.019 µg/mL in the left heart blood and 3.157 µg/mL and 0.002 µg/mL in right heart blood. In this case, the nicotine concentrations in blood reached the lethal level. The distributions of nicotine and cotinine, as indicated by the intravenous injection, were related to the distribution of organs that metabolize nicotine and the distribution of nicotinic acetylcholine receptors.

Pericardial fluids or Cardiopulmonary Bypass-Is There a Major Culprit for Changes in Coagulation and Inflammation?

BACKGROUND: From the results of a previous study, it remained to be investigated if a perioperative rise of few tested coagulation and inflammation markers is caused by conventional cardiopulmonary bypass (CPB) itself or rather by direct recirculation of pericardial fluids. METHODS: Forty-eight patients operated on with conventional CPB for myocardial revascularization were randomized either for direct recirculation of pericardial suction fluids or for cell saving (CS). RESULTS: Thrombin-antithrombin complexes showed lower values intraoperatively in the CS group (p < 0.0001), and D-dimers tended to remain lower at intensive care unit arrival (p = 0.095). Tests of inflammation markers were less meaningful. CONCLUSION: Direct recirculation of pericardial fluids rather than conventional CPB itself causes major intraoperative changes of some coagulation markers. Pericardial blood loss with direct recirculation should be kept to a minimum to avoid unnecessary activation of coagulation. Inflammation markers need further investigations.

mRNA expression patterns in human myocardial tissue, pericardial fluid and blood, and its contribution to the diagnosis of cause of death.

Gene expression has become an interesting research area in forensic pathology to investigate the process of death at the molecular level. The aims of this study were to analyze changes in gene expression patterns in relation to the cause of death, and to propose new molecular markers of myocardial ischemia of potential use for the postmortem diagnosis of early ischemic heart damage in cases of sudden cardiac death (SCD). We determined mRNA levels of five proteins related with ischemic myocardial damage and repair - TNNI3, MYL3, TGFB1, MMP9 and VEGFA - in specific sites of the myocardium, blood and pericardial fluid in samples from 30 cadavers with different causes of death (SCD, multiple trauma, mechanical asphyxia, and other natural deaths). TNNI3 expression in blood, and MMP9 expression in pericardial fluid, were significantly higher when the cause of death was mechanical asphyxia, probably because of the more sensitive response of these proteins to acute systemic hypoxia/ischemia. Specifically, among SCD cases, increased MYL3, VEGFA and MMP9 values in the anterior wall of the right ventricle were found when the confirmed cause of death was acute myocardial infarction (AMI). Higher TGFB1 expression was found in the interventricular septum when AMI was not the cause of death, most likely as a reflection of the short duration of ischemia. Molecular biology techniques can provide complementary tools for the forensic diagnosis of early ischemic myocardial damage and AMI, and may make it possible to determine the duration and severity of myocardial ischemia.

Human pericardial proteoglycan 4 (lubricin): Implications for postcardiotomy intrathoracic adhesion formation.

OBJECTIVE: Intrapericardial fibrous adhesions increase the risk of sternal reentry. Proteoglycan 4/lubricin (PRG4) is a mucin-like glycoprotein that lubricates tissue compartments and prevents inflammation. We characterized PRG4 expression in human pericardium and examined its effects in vitro on human cardiac myofibroblast fibrotic activity and in vivo as a measure of its therapeutic potential to prevent adhesions. METHODS: Full-length PRG4 expression was determined using Western blot analysis and amplified luminescent proximity homogeneous assay in human pericardial tissues obtained at cardiotomy. The in vitro effects of PRG4 were investigated on human cardiac myofibroblasts for cell adhesion, collagen gel contraction, and cell-mediated extracellular matrix remodeling. The influence of PRG4 on pericardial homeostasis was determined in a chronic porcine animal model. RESULTS: PRG4 is expressed in human pericardial fluid and colocalized with pericardial mesothelial cells. Recombinant human PRG4 prevented human cardiac myofibroblast attachment and reduced myofibroblast activity assessed using collagen gel contraction assay (64.6% ± 8.1% vs 47.1% ± 6.8%; P = .02). Using a microgel assay, human cardiac myofibroblast mediated collagen fiber remodeling was attenuated by PRG4 (1.17 ± 0.03 vs 0.90 ± 0.05; P = .002). In vivo, removal of pericardial fluid alone induced severe intrapericardial adhesion formation, tissue thickening, and inflammatory fluid collections. Restoration of intrapericardial PRG4 was protective against fibrous adhesions and preserved the pericardial space. CONCLUSIONS: For the first time, we show that PRG4 is expressed in human pericardial fluid and regulates local fibrotic myofibroblast activity. Loss of PRG4-enriched pericardial fluid after cardiotomy might induce adhesion formation. Therapeutic restoration of intrapericardial PRG4 might prevent fibrous/inflammatory adhesions and reduce the risk of sternal reentry.

Alpha-fetoprotein in pericardial, peritoneal, and pleural fluids: A body fluid matrix evaluation.

OBJECTIVES: Alpha-fetoprotein (AFP) measurement in pericardial, peritoneal (ascites), and pleural fluids is sometimes requested by clinicians as supportive evidence in the evaluation of suspected malignancy. As commercially available, Food and Drug Administration (FDA)-cleared AFP assays are not validated for these fluid types, laboratories must complete additional validation studies to comply with regulatory requirements for body fluid testing. The objective of this study was therefore to conduct a matrix evaluation for these body fluid types using the Beckman Access AFP assay on the UniCel DxI 800 immunoassay system. DESIGN AND METHODS: Using an Institutional Review Board (IRB) approved protocol, previously collected pericardial fluid, peritoneal fluid, pleural fluid, and serum specimens were de-identified and frozen at -20 °C prior to matrix evaluation experiments. Spiked recovery, mixed recovery/linearity, and precision studies were conducted. RESULTS: In spiked and mixed recovery studies, the average percent (%) recovery was within predefined acceptable limits (±15%) for all three body fluids. Linearity was observed over the analytical measurement range (AMR) for all three body fluids (slope, intercept, systematic error): pericardial 0.988, -0.1, 6.1%; peritoneal 0.986, 0.0, 4.1%; and pleural 1.016, 0.0, 1.6%. Imprecision was ≤6.0% CV for all three body fluids at both high and low AFP concentrations. CONCLUSIONS: Matrix interference with AFP testing was not observed for pericardial, peritoneal, or pleural fluids on the Beckman UniCel DxI 800 system.

Human Pericardial Fluid Contains Exosomes Enriched with Cardiovascular-Expressed MicroRNAs and Promotes Therapeutic Angiogenesis.

The pericardial fluid (PF) is contained in the pericardial sac surrounding the heart. MicroRNA (miRNA) exchange via exosomes (endogenous nanoparticles) contributes to cell-to-cell communication. We investigated the hypotheses that the PF is enriched with miRNAs secreted by the heart and that it mediates vascular responses through exosome exchange of miRNAs. The study was developed using leftover material from aortic valve surgery. We found that in comparison with peripheral plasma, the PF contains exosomes enriched with miRNAs co-expressed in patients' myocardium and vasculature. At a functional level, PF exosomes improved survival, proliferation, and networking of cultured endothelial cells (ECs) and restored the angiogenic capacity of ECs depleted (via Dicer silencing) of their endogenous miRNA content. Moreover, PF exosomes improved post-ischemic blood flow recovery and angiogenesis in mice. Mechanistically, (1) let-7b-5p is proangiogenic and inhibits its target gene, TGFBR1, in ECs; (2) PF exosomes transfer a functional let-7b-5p to ECs, thus reducing their TGFBR1 expression; and (3) let-7b-5p depletion in PF exosomes impairs the angiogenic response to these nanoparticles. Collectively, our data support the concept that PF exosomes orchestrate vascular repair via miRNA transfer.

Evaluation of Pericardial Fluid C-Type Natriuretic Peptide Levels in Patients Undergoing Coronary Bypass Surgery.

Background Neurohumoral and hemodynamic mechanisms have an effect on cardiac activity. C-type natriuretic peptide (CNP) is accessible in the cardiovascular system. The aim of this study was to determine whether CNP concentrations in pericardial fluid and blood are related to cardiac dysfunction in patients undergoing coronary artery bypass graft surgery. Materials and Methods In this study, 40 patients undergoing coronary artery bypass grafting were enrolled. The patients were separated into two groups according to left ventricular (LV) ejection fraction (EF): group 1 contained 28 patients with normal LV systolic function (LVEF ≥ 50%) and group 2 contained 12 patients with impaired LV systolic function (LVEF < 45%). Plasma and pericardial fluid samples were acquired during surgery to measure CNP levels. Results In group 1, CNP levels were detected to be 0.46 ± 0.10 ng/mL in plasma and 0.66 ± 0.8 ng/mL in pericardial liquid. In group 2, these levels were 0.51 ± 0.09 and 0.79 ± 0.12 ng/mL, respectively. CNP levels were determined to be significantly higher in patients with low EF compared with those with normal EF in pericardial fluid concentrations (p = 0.013). Conclusions CNP level in pericardial fluid is a more sensitive and proper marker of LV dysfunction than CNP levels in plasma. To the best of our knowledge, this study is the first to examine pericardial fluid CNP levels in patients undergoing coronary artery bypass surgery. It may have a valuable role in organizing cardiac remodeling and hypertrophy.

Relationship between site of myocardial infarction, left ventricular function and cytokine levels in patients undergoing coronary artery surgery.

BACKGROUND: The purpose of this study was to examine the relationship between left ventricular (LV) function, cytokine levels and site of myocardial infarction (MI) in patients undergoing coronary artery bypass grafting (CABG). METHODS: Sixty patients undergoing CABG were divided into three groups (n = 20) according to their history of site of myocardial infarction (MI): no previous MI, anterior MI and posterior/inferior MI. In the pre-operative period, detailed analysis of LV function was done by transthoracic echocardiography. The levels of adrenomedullin, interleukin-1-beta, interleukin-6, tumour necrosis factor-alpha (TNF-α) and angiotensin-II in both peripheral blood samples and pericardial fluid were also measured. RESULTS: Echocardiographic analyses showed that the anterior MI group had significantly worse LV function than both the group with no previous MI and the posterior/inferior MI group (p < 0.05 for LV end-systolic diameter, fractional shortening, LV end-systolic volume, LV end-systolic volume index and ejection fraction). In the anterior MI group, both plasma and pericardial fluid levels of adrenomedullin and and pericardial fluid levels of interleukin-6 and interleukin- 1-beta were significantly higher than those in the group with no previous MI (p < 0.05), and pericardial fluid levels of adrenomedullin, interleukin-6 and interleukin-1-beta were significantly higher than those in the posterior/inferior MI group (p < 0.05). CONCLUSIONS: The results of this study indicate that (1) patients with an anterior MI had worse LV function than patients with no previous MI and those with a posterior/inferior MI, and (2) cytokine levels in the plasma and pericardial fluid in patients with anterior MI were increased compared to patients with no previous MI.

Adipokine Imbalance in the Pericardial Cavity of Cardiac and Vascular Disease Patients.

AIM: Obesity and especially hypertrophy of epicardial adipose tissue accelerate coronary atherogenesis. We aimed at comparing levels of inflammatory and atherogenic hormones from adipose tissue in the pericardial fluid and circulation of cardiovascular disease patients. METHODS AND RESULTS: Venous plasma (P) and pericardial fluid (PF) were obtained from elective cardiothoracic surgery patients (n = 37). Concentrations of leptin, adipocyte fatty acid-binding protein (A-FABP) and adiponectin (APN) were determined by enzyme-linked immunosorbent assays (ELISA). The median concentration of leptin in PF (4.3 (interquartile range: 2.8-9.1) µg/L) was comparable to that in P (5.9 (2.2-11) µg/L) and these were significantly correlated to most of the same patient characteristics. The concentration of A-FABP was markedly higher (73 (28-124) versus 8.4 (5.2-14) µg/L) and that of APN was markedly lower (2.8 (1.7-4.2) versus 13 (7.2-19) mg/L) in PF compared to P. APN in PF was unlike in P not significantly related to age, body mass index, plasma triglycerides or coronary artery disease. PF levels of APN, but not A-FABP, were related to the size of paracardial adipocytes. PF levels of APN and A-FABP were not related to the immunoreactivity of paracardial adipocytes for these proteins. CONCLUSION: In cardiac and vascular disease patients, PF is enriched in A-FABP and poor in APN. This adipokine microenvironment is more likely determined by the heart than by the circulation or paracardial adipose tissue.

Cardiac troponin T determination by a highly sensitive assay in postmortem serum and pericardial fluid.

PURPOSE: The main objective of this study was to test, for the first time, a highly sensitive cardiac troponin T (cTnThs) assay in postmortem serum and pericardial fluid and to evaluate cardiac troponin T (cTnT) levels and their stability after death at different postmortem intervals, in an attempt to determine the viability of the cTnThs assay in the postmortem diagnosis of the cause of death. METHODS: cTnT levels were determined in serum and pericardial fluid samples taken from 58 cadavers at known postmortem intervals, whose causes of death were categorized into the following groups: (1) sudden cardiac deaths, (2) multiple trauma, (3) mechanical asphyxia, and (4) other natural deaths. cTnT was determined by inmunoassay, using the Troponin T highly sensitive STAT assay (Roche(®)). RESULTS: Average cTnT levels measured by a highly sensitive assay in postmortem serum were markedly higher than clinical serum levels. Moreover, similar results, higher cTnT levels in postmortem pericardial fluid, were obtained when compared to levels found in pericardial fluid taken from two living patients during coronary artery bypass surgery. cTnT levels in both postmortem fluids remained stable for up to 34 h after death. No differences in cTnT levels in either postmortem fluid by sex and age were detected. Levels of cTnT found in pericardial fluid in the other natural deaths group were significantly lower than the cTnT levels found in that postmortem fluid from any of the other causes of death groups. CONCLUSION: It is therefore reasonable to conclude that determination of cTnT by a highly sensitive assay in pericardial fluid can provide forensic pathologists with a complementary test to the diagnosis of cause of death.

Expression Patterns of miRNA-423-5p in the Serum and Pericardial Fluid in Patients Undergoing Cardiac Surgery.

BACKGROUND: Recently, it has been reported that specific microRNA (miRNA) levels are elevated in serum and can be used as biomarkers in patients with cardiovascular diseases. However, miRNAs expression profiles and their sources in pericardial fluid (PF) are unclear. METHODS AND RESULTS: The purpose of this study was to identify the levels of miRNAs in PF in relation to those in the serum in patients undergoing cardiac surgery. Serum (S) and PF from patients undergoing coronary artery bypass graft (CABG) due to stable angina pectoris (sAP) and unstable AP (uAP) and aortic valve replacement due to aortic stenosis (AS) were analyzed for the detection of miRNAs. We named these samples S-sAP, S-uAP, S-AS, PF-sAP, PF-uAP, and PF-AS, respectively. We first measured the levels of miR-423-5p, which was recognized previously as a biomarker for heart failure. miR-423-5p levels were significantly higher in PF than serum. Although there was no difference in miR-423-5p levels among the PF-AS, PF-sAP, and PF-uAP, its levels were significantly elevated in S-uAP compared with those in S-AS and S-sAP. In order to clarify the source of miR-423-5p in PF, we measured the levels of muscle-enriched miR-133a and vascular-enriched miR-126 and miR-92a in the same samples. miR-133a levels were significantly higher in serum than in PF, and it was elevated in S-uAP compared with S-AS. miR-126 level was significantly increased in serum compared with PF, and the level of miR-92a the similar tendency. miR-423-5p is located in the first intron of NSRP1. There is another miRNA, miR-3184, encoded in the opposite direction in the same region. In vitro experiments indicated that the duplex of miR-423-5p and miR-3184-3p was more resistant to RNase than the duplex of miR-423-5p and miR-133-3p, which may help to stabilize miR-423-5p in the PF. CONCLUSIONS: Our results suggested that miR-423-5p is enriched in PF, and serum miR-423-5p may be associate with uAP. Its expression pattern was different to that of muscle- and vascular-enriched miRNAs, miR-133a, miR-126, and miR-92a.

Cytologic and Immunophenotypic Features of Malignant Cells in Pediatric Body Fluids.

OBJECTIVE: Cytospin preparations and immunocytochemistry are common methods in hospitals to evaluate malignancies in body fluids. Characteristics of malignant cells in pediatric body fluids have not been adequately evaluated. STUDY DESIGN: 183 pleural, peritoneal and pericardial pediatric fluid specimens were examined by cytospin preparations and immunocytochemistry from two hospitals using similar procedural techniques. Cytologic diagnoses were correlated with the results of clinical history, histology and ancillary studies. RESULTS: Forty cases with malignancy were identified (21.9%); the most common diagnoses were rhabdomyosarcoma and acute lymphoblastic lymphoma (9 and 8 cases, respectively). Small round cell tumors revealed similar morphology as clusters of small round cells with central nuclei and scant cytoplasm with frequent small vacuoles. Twenty-one cases were evaluated by immunocytochemistry, 12 by flow cytometry and 5 by cytogenetic analysis. CD3, CD20, TdT, CD10, desmin and myogenin were the most common markers. Staining artifacts causing interpretation difficulties were noted in 5 cases that were resolved by molecular studies and deferral for surgical specimens. CONCLUSIONS: Small round cell tumors are the most common malignancies encountered in pediatric body fluids and share a nonspecific morphology. Although immunocytochemistry is helpful to arrive at the correct diagnosis, other ancillary studies may be necessary, particularly in hematologic malignancies and other difficult cases.

Decreased Bioenergetic Health Index in monocytes isolated from the pericardial fluid and blood of post-operative cardiac surgery patients.

Monitoring the bioenergetics of leucocytes is now emerging as an important approach in translational research to detect mitochondrial dysfunction in blood or other patient samples. Using the mitochondrial stress test, which involves the sequential addition of mitochondrial inhibitors to adherent leucocytes, we have calculated a single value, the Bioenergetic Health Index (BHI), which represents the mitochondrial function in cells isolated from patients. In the present report, we assess the BHI of monocytes isolated from the post-operative blood and post-operative pericardial fluid (PO-PCF) from patients undergoing cardiac surgery. Analysis of the bioenergetics of monocytes isolated from patients' PO-PCF revealed a profound decrease in mitochondrial function compared with monocytes isolated from their blood or from healthy controls. Further, patient blood monocytes showed no significant difference in the individual energetic parameters from the mitochondrial stress test but, when integrated into the BHI evaluation, there was a significant decrease in BHI compared with healthy control monocytes. These data support the utility of BHI measurements in integrating the individual parameters from the mitochondrial stress test into a single value. Supporting our previous finding that the PO-PCF is pro-oxidant, we found that exposure of rat cardiomyocytes to PO-PCF caused a significant loss of mitochondrial membrane potential and increased reactive oxygen species (ROS). These findings support the hypothesis that integrated measures of bioenergetic health could have prognostic and diagnostic value in translational bioenergetics.