Matrine inhibits disturbed flow-enhanced migration via downregulation of ERK1/2-MLCK signaling vascular smooth muscle cells.

BACKGROUND: To investigate the effects of matrine on the vascular smooth muscle cell (VSMC) migration modulated by disturbed flow and their underlying molecular mechanisms in vitro. METHODS: Isolated rat aortic VSMCs were grown to confluence on 20- × 80-mm fibronectin-coated glass cover slides, and then, denuded zones were made at the position calculated to be the oscillating flow-reattachment zone and also in the downstream laminar flow region. VSMCs were treated with different doses of matrine (0, 10, 20, 30, and 40 mg/L), or PD98059 (30 µM), ML-7 (10 µM) combined with matrine (40 mg/L) for 30 minutes before and during the experiments. Then, the wounded monolayers were kept under static conditions or were subjected to laminar or disturbed flow for 21 hours or 10 hours. The VSMC migration was assessed by microscopic images. The extracellular signal-regulated kinase 1/2 (ERK1/2) and myosin light chain kinase (MLCK) proteins were determined by Western blot. RESULTS: Disturbed flow significantly increased phosphorylation of ERK1/2. Selective inhibition of ERK1/2 phosphorylation by inhibitor PD98059 and matrine significantly suppressed VSMC migration under disturbed flow. Disturbed flow significantly enhanced phosphorylation of MLCK, whereas both matrine and PD98059 inhibited the phosphorylation of MLCK under disturbed flow. The complete inhibition of MLCK phosphorylation using the selective MLCK inhibitor ML-7 significantly inhibited VSMC migration under disturbed flow. CONCLUSION: Matrine inhibits VSMC migration under disturbed flow, in part, by downregulation of ERK1/2-MLCK signaling pathway.

Cardioprotective effect of a hemoglobin-based oxygen carrier on cold ischemia/reperfusion injury.

OBJECTIVES: The etiology of myocardial ischemia/reperfusion (I/R) injury is multifactorial, but activation of the innate immune system and the resulting inflammatory response are important components of I/R injury. The aim of this study was to investigate the protective effect of a hemoglobin-based oxygen carrier (HBOC) on cold I/R heart and to explore the underlying mechanisms. METHODS: Isolated Sprague-Dawley rat hearts were perfused in the Langendorff mode. After 30 min of basal perfusion, rat hearts were arrested with histidine-tryptophan-ketoglutarate solution (HTKs) with or without an HBOC and hypothermically stored (4°C) for 9 or 14 h, followed by 2 h of reperfusion. RESULTS: Compared with HTKs alone, the HBOC in HTKs greatly improved heart contraction and decreased infarct size, necrosis and apoptosis, which was related to the reduced expression of Toll-like receptor 2 (TLR 2), TLR 4, TNF-α, IL-1ß and nuclear factor-κB (NF-κB) activation. CONCLUSIONS: Our results demonstrated that the HBOC protected isolated rat heart from cold I/R injury and this protection was associated with attenuation of the expression of the TLR 2 and TLR 4/NF-κB signaling pathway, which may down-regulate the inflammatory response.

Polymerised placenta haemoglobin attenuates cold ischaemia/reperfusion injury in isolated rat heart.

Ischaemia/reperfusion (I/R) injury is harmful to the cardiovascular system and is responsible for the inflammatory response, which, in turn, aggravates cardiac dysfunction. This study was designed to investigate the protective effect and potential mechanism of a haemoglobin-based oxygen carrier on cold I/R-injured hearts. Isolated Sprague-Dawley rat hearts were perfused in Langendorff mode. After a 30-min basal perfusion, rat hearts were arrested and hypothermically stored at 4°C for 12h followed by a 2-h reperfusion. Compared with histidine-tryptophan-ketoglutarate solution (HTKs), polymerised placenta haemoglobin (PolyPHb) in HTKs greatly improved heart contraction and decreased infarction size, necrosis, and apoptosis, which was related to reduced expression of TLR2, TLR4, TNF-α, and IL-1ß, and NF-κB activation. Our results demonstrate the cardioprotective effect of PolyPHb on cold I/R-injured hearts and revealed that this protection was mediated in large part by attenuation of TLR2 and -4/NF-κB signalling pathway and could possibly down-regulate the inflammatory response.

[Early surgical outcomes of coronary heart disease with severe ischemic mitral regurgitation].

OBJECTIVE: To summarize the experience with surgical treatment of coronary artery disease with severe ischemic mitral valve regurgitation (IMR). METHODS: From January 2006 to December 2009, 45 patients (35 males, 10 females aged 32-74 years) with the diagnosis of coronary artery disease complicated by IMR underwent coronary artery bypass grafting (CABG) combined with mitral valve plasty (MVP, 24 cases) or mitral valve replacement (MVR, 21 cases). RESULTS: Perioperative deaths occurred in 2 cases due to multiple organ failure (MOF). Echocardiography showed a significant reduction of the mitral regurgitation area (from 11.80∓2.45 cm(2) to 2.83∓0.98 cm(2), t=22.80, P=0.00) after CABG combined with mitral valve surgery, with also significantly reduced postoperative left ventricular end diastolic diameter (LVEDD) (from 57.61∓10.06 mm to 51.84∓8.98 mm, t=2.85, P=0.005). No significant difference was detected in the left ventricular ejection fraction after the operation [(52.7∓15.4)% vs (53.2∓13.2)%, t=0.16, P=0.87)]. CONCLUSIONS: CABG combined with mitral valve surgery can improve early postoperative left ventricular function in patients with ischemic coronary heart disease complicated by severe mitral regurgitation, but further follow-up study is still needed for evaluation of the long-term results.

[Expression and functional role of small conductance Ca(2+)-activated K(+) channels in human atrial myocytes].

OBJECTIVE: To investigate the expression and functional role of the small conductance Ca(2+)-activated K(+) channels in human atrial myocytes. METHODS: We collected the right atrial appendage tissues from 8 patients with congenital heart defect with sinus rhythm undergoing open-heart surgery. Immunohistochemistry was performed to identify the expression of 3 isoforms of SK channel (SK1, SK2 and SK3). Using the classical two-step enzymatic isolation method, perforated patch clamp and conventional voltage-clamp techniques were performed to record the action potentials (APs) and the whole-cell Ca(2+)-activated K(+) current (I(K, Ca)) in the single atrial myocyte. We compared the changes in action potential duration (APD) before and after the application of a specific SK channels blocker apamin (100 nmol/L). RESULTS: Human atrial myocytes showed positivity for all the SK1, SK2 and SK3 isoform channels. Patch-clamp recording confirmed the presence of I(K,Ca), and apamin significantly prolonged APD at 90% repolarization (APD(90)), but produced no obvious effect on APD(50). CONCLUSION: The three isoforms of SK channels are all expressed in human atrial myocytes. SK channels play a prominent role in the late phase of repolarization in human atrial myocytes, which is distinct from their functional roles in neurons where they mediate the process of afterhyperpolarization following APs.

Determination of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry.

A sensitive and rapid method was developed for quantification of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS). An aliquot of 1 mL plasma sample was extracted with ethyl acetate-dichloromethane. Separation of olprinone and the milrinone (internal standard, IS) from the interferences was achieved on a C(18) column followed by MS/MS detection. The analytes were monitored in the positive ionization mode. Multiple reaction monitoring using the transition of m/z 251 → m/z 155 and m/z 212 → m/z 140 was performed to quantify olprinone and IS, respectively. The method had a total chromatographic run time of 3 min and linear calibration curves over the concentration range of 0.5-60 ng/mL. The lower limit of quantification (LLOQ) was 0.5 ng/mL. The intra- and inter-day precisions were less than 16.3% for low QC level, and 7.1% for other QC levels, respectively. The intra- and inter-day relative errors were ranged between -12.2% and 3.7% for three QC concentration levels. The validated method was successfully applied to the quantification of olprinone concentration in human plasma after intravenous (i.v.) administration of olprinone at a constant rate of infusion of 2 µg/(kg min) for 5 min in order to evaluate the pharmacokinetics.

[Early and mid-term results after 17 mm St Jude Regent mechanical valve replacement in 44 patients with small aortic root].

OBJECTIVE: To analyze the changes in the cardiac function after St. Jude Regent mechanical valve replacement and assess the prosthesis-patient matching. METHODS: From October 2007 to March 2009, 44 patients received implantation of 17 mm St. Jude aortic prostheses in our hospital. The patients were followed up for clinical symptoms, signs, electrocardiogram (ECG), echocardiogram and cardiac functions, and the results were compared with those of randomly selected 44 patients receiving 21 mm St. Jude aortic prostheses. RESULTS: In 17 mm St Jude Medica Regent valve group, 8 patients presented with ECG ST segment changes, 3 complained of chest tightness, 3 had occasional chest pain and discomfort, and 8 had grade II and 4 grade III cardiac function. In 21 mm St Jude Medical Regent valve group, 6 patients had ECG ST segment changes, 2 complained of chest tightness, 2 reported occasional chest pain and discomfort, 11 had grade II and 2 grade III cardiac function. No significant differences were found in these indices between the two groups (P=0.32). Compared with those before operation, the two groups showed significant improvements in the left ventricular end-diastolic diameter, left ventricular posterior wall thickness, left ventricular mass index, and aortic pressure gradient (P<0.05). A significant increase in the left ventricular ejection fraction occurred 6-12 months after operation, but without statistical difference between the two groups (P>0.05). CONCLUSION: For underweight patients (<60 kg) and those with small body surface area (<1.6 cm(2)), 17 mm St. Jude Medical Regent valve prosthesis may produce good therapeutic effect, and some indices are even close to those after placement of 21 mm St. Jude Medical Regent valve prosthesis. No obvious prosthesis-patient mismatch occurs after the placement of the 17 mm valve prosthesis and aortic valve ring expansion is not necessary.

[Surgical treatment of 128 cases of constrictive pericarditis].

OBJECTIVE: To summarize the experience with surgical treatment of constrictive pericarditis. METHODS: A retrospective analysis of the post-operative clinical data was conducted in 128 surgical patients with chronic constrictive pericarditis. RESULTS: Two early postoperative death occurred in this group due to severe low cardiac output syndrome, with the mortality rate of 1.57%. The postoperative complications included low cardiac output syndrome (13.2%), arrhythmia (7.02%), acute renal insufficiency (3.9%), respiratory insufficiency (3.1%), wound infection (2.3%), postoperative chest bleeding (1.6%) and cerebral infarction (0.78%). Relapse occurred in one case because of incomplete pericardial resection. CONCLUSIONS: Constrictive pericarditis should be confirmed as soon as possible with actively surgery, and the extent of pericardial resection should be decided according to the individual conditions. Complete untethering of the diseased pericardium should be performed with active prevention of postoperative complications.

The short-term pulsatile ventricular assist device for postcardiotomy cardiogenic shock: a clinical trial in China.

Despite the recent advances in myocardial protection, surgical techniques, intra-aortic balloon therapy, and maximal pharmacological support, postoperative ventricular dysfunction continues to occur in 0.5-1.0% of all patients undergoing cardiac surgery. Ventricular assist device (VAD) is an important therapeutic adjunct in treating patients with profound ventricular dysfunction with postcardiotomy cardiogenic shock. The purpose of this report was to describe the clinical results with the China-made Luo-Ye VAD as a short-term circulatory support. From May 1998 to December 2006, 17 patients with postcardiotomy cardiogenic shock were supported by the Luo-Ye VAD. Of these patients, 10 were males and seven were females with a mean age of 49.6 years (range 36-68 years). All cases were supported by left VAD (LVAD). Mean duration of support was 46.3 h (range 13-113 h). A criteria of insertion was established to standardize implantation criteria. Among the 17 patients treated with LVAD, eight (47.1%) patients were weaned from support and seven (41.2%) patients were discharged from hospital. Ten (58.8%) patients died while on LVAD support (nine cases) or shortly after weaning (one case). The causes of death in the entire group were cardiac (40%), renal failure (20%), neurologic (10%), sepsis (10%), and multiple organ system failure (20%). The complications were represented by bleeding, renal failure, neurologic event, infection, ventricular arrhythmias, etc. The Luo-Ye VAD functioned well and proved to be useful in patients with postcardiotomy cardiogenic shock. It carries a less-postoperative anticoagulant and a low incidence of VAD-related complications. The survival rate was encouraging in our small cohort of patients.

[Transepicardial autologous transplantation of bone marrow mononuclear cells for acute myocardial infarction].

OBJECTIVE: To test the effect of intramyocardial injection of autologous bone marrow mononuclear cells (MNCs) in improving the cardiac function and myocardial revascularization in miniswine models of myocardial infarction. METHODS: The miniswine models of myocardial infarction established by ligation of the anterior descending coronary artery were divided into 3 groups including a control and two MNC injection groups. Autologous bone marrow MNCs were injected via the epicardium into the infarcted area in the latter two groups at 1 and 2 weeks after the infarction, respectively. The ventricular segmental wall motion was evaluated after the treatment, and the infarcted myocardium observed with immunohistochemistry on frozen sections. RESULTS: The left ventricular segmental wall motion differed significantly between the control and the MNC injection groups at 1 and 2 months after the treatment. CM-DiI-positive cells were detected in the infarcted myocardium where MNCs were implanted. CONCLUSION: Intramyocardial injection of autologous bone marrow MNCs improves the infarcted ventricular segmental wall motion, and significantly increases the number of blood vessels in the infracted area. The transplanted cells can be integrated into the vascular walls of the capillaries and arterioles and differentiate into cardiomyocytes.

[Perivenous support with autologous pericardium inhibits neointimal thickening in canine vein grafts].

OBJECTIVE: To observe the effect of perivenous support with autologous pericardium on neointimal thickening in canine vein grafts. METHODS: An autologous pericardium graft of 7 cm x 4 cm was harvested in right anterolateral thoracotomy. Two equal segments of the jugular vein were transplanted to both sides of the femoral arteries in 12 dogs, and on one side of the vein graft, perivenous support with autologous pericardium was applied. The vein grafts were harvested 2 and 4 weeks after operation and the thickness and area of the neointima calculated using computerized image analysis system. Scanning electron microscopy and PCNA immunohistochemistry were also performed. RESULTS: The thickness and area of the neointima were significantly greater in the control grafts than in the grafts with perivenous support (P<0.05), and the proliferation of vascular smooth muscle cells in the supported graft was less active (P<0.05). Electron microscopy showed extensive destruction of the endothelium in the control graft, but only slight damage was found in the graft with perivenous support. CONCLUSION: Perivenous support of the vein graft with autologous pericardium can reduce intimal and medial hyperplasia in the graft.

[Clinical analysis of gastrointestinal bleeding after cardiac surgery].

OBJECTIVE: To explore early diagnosis, treatment and prevention of gastrointestinal (GI) bleeding after cardiac surgery. METHODS: In the last 13 years, cases complicated with GI bleeding after cardiac surgeries were analyzed retrospectively. RESULTS: Fourty-four GI bleeding occurred post-operatively in (6 +/- 3) d. The mortality was 23% (10/44). Thirty-eight were located in upper GI tract, of them 26 underwent conservative therapy while 4 died of other than GI bleeding cause; six underwent laparotomy while 1 and 3 died of septicemia and multi-organ failure respectively; six underwent gastric endoscopic hemostasis by electrocautery or clipping the bleeding vessel while all survived. Six were located in lower GI tract, and 2 of them underwent laparotomy without finding bleeding section and died of multi-organ failure. By multivariable logistic regression analysis, deaths were highly related to the post-operative ventilator-dependence, acute renal insufficiency, intra-aortic balloon pump (IABP) assisting and laparotomy. CONCLUSION: The mortality of GI bleeding after cardiac surgeries is very high, early gastrointestinal endoscopic examination and minimally invasive intervention can treat this complication more effectively. GI bleeding must be prevented whenever complicating post-operative ventilator-dependence, acute renal insufficiency, and IABP assisting after cardiac surgery.

[Aortic-coronary sinus shunt retroperfusion protects against acute myocardial ischemia in pigs during off-pump beating heart surgery].

OBJECTIVE: To investigate the protective effect and safety of coronary sinus retroperfusion (CSR) with aortic oxygenated blood for acute myocardial ischemia during off-pump beating heart surgery in pigs. METHODS: Eighteen pigs were subjected to 120 min of acute myocardial ischemia by ligation of the lateral anterior descending branch (LAD) of the coronary artery followed by 60 min of reperfusion by lifting LAD ligation. The pigs were divided into 3 groups after the above operation, including a control group (group 1) and low- and high-pressure retroperfusion groups (groups 2 and 3), and in the latter two groups the pigs received 60 min of aorta-coronary sinus shunt retroperfusion (ACSSR) following 60 min of ischemia with self or manually inflated balloon-tipped cannula inserted to induce low or high-pressure, respectively. The left ventricular function and measurements of coronary sinus nitric oxide (NO), endothelin-1 (ET-1) and infarct size were recorded. RESULTS: Three hours after ischemia, the maximal left ventricular pressure increment to reduction rates in groups 2 and 3 were much higher than those of group 1, with also higher NO and lower ET-1 concentrations in the coronary sinus blood. The infarct size was reduced by 45%; and 61%; in groups 2 and 3, respectively, as compared with that of group 1. CONCLUSION: ACSSR can reduce left ventricular systolic and diastolic dysfunction, protect coronary endothelial function, and reduce infarct size for rescue of the acutely ischemic myocardium in pigs during off-pump beating heart surgery.

Surgical treatment of late tricuspid regurgitation after left cardiac valve replacement.

BACKGROUND: The development of late tricuspid regurgitation (TR) following left cardiac valve replacement is an important complication, as it is associated with a severe impairment of exercise capacity and a poor symptomatic outcome. The pathogenesis of this condition remains poorly defined. It is still a challenge in terms of its prevention, treatment and indications for surgical correction. AIMS: To investigate the possible pathogenesis and report the surgical results of the late TR after left cardiac valve replacement. METHODS: There were 56 patients with moderate to severe TR after left cardiac valve replacement, divided into normal prosthesis group (10 patients with normal prosthetic valve function) and dysfunctional prosthesis group (46 patients with prosthetic valve dysfunction). In the normal prosthesis group, 4 patients underwent mitral valve replacement (MVR) and 6 patients underwent combined mitral and aortic valve replacement (DVR). Patients in the dysfunctional prosthesis group included MVR in 36, aortic valve replacement (AVR) in 4 and DVR in 6, with bioprosthetic valve dysfunction occurring in 18, mechanical prosthetic valve obstruction in 22 and periprosthetic valve leakage in 6 patients. At the initial operation, 10 patients underwent DeVega's tricuspid annuloplasty and 46 patients' tricuspid valves were normal. At the second operation, the surgical treatment of TR included tricuspid valve replacement (TVR) in 9 and tricuspid annuloplasty in 47. RESULTS: Two patients died postoperatively giving a 3.6% hospital mortality. The 54 survivors were followed up for 6-132 months (mean of 79.4 months). Heart function improved significantly in 8 with TVR and in 40 with tricuspid annuloplasty. Echocardiography showed moderate TR in 5 and severe TR in 1 patient with tricuspid annuloplasty who need a further surgical treatment. CONCLUSION: Pulmonary hypertension, myocardial dysfunction, and atrial fibrillation might be responsible for the development of late TR after left cardiac valve replacement. Tricuspid annuloplasty, as the surgical method of first choice, resulted in improvement in 87% of patients with late TR after left cardiac valve replacement. TVR can also be safely applied to repair organic disease and the extremely dilated tricuspid valve annulus. If the TR area is more than 25cm(2), the TVR is recommended.