The state of platelets preserved in extracorporeal circulation with a glycoprotein IIb/IIIa inhibitor.

INTRODUCTION: Temporary inhibition of platelet function during extracorporeal circulation (platelet anesthesia) can preserve platelet count. We hypothesized that platelet anesthesia with a glycoprotein IIb/IIIa inhibitor could preserve activated platelets. MATERIALS AND METHODS: Fresh human blood from donors was recirculated for 120 min in a simulated extracorporeal circuit. Heparin and FK633, a short-acting platelet glycoprotein IIb/IIIa inhibitor, were added to recirculated blood in one group (group F, n=5) whereas only heparin was used in controls (group C, n=5). Blood samples were obtained from the donors, and at 0, 5, 15, 30, 60, and 120 min of recirculation. Platelet counts, beta-thromboglobulin, thrombin-antithrombin complex, and aggregation to adenosine diphosphate were measured. Flow cytometry was performed for measurement of fibrinogen binding, platelet surface expression of P-selectin, and microparticles. RESULTS AND CONCLUSIONS: In the FK633 group, platelet counts were preserved and beta-thromboglobulin levels remained unchanged, whereas in group C, platelet counts decreased significantly and beta-thromboglobulin increased significantly from 30 and 60 min, respectively. FK633 inhibited platelet aggregation and fibrinogen binding to platelets throughout recirculation. A significant difference between groups with respect to microparticle parameters and thrombin-antithrombin complex levels was evident by 120 min. P-selectin expression increased at 0 min in both groups, and was preserved significantly at 5 min and reduced at 120 min in group F. Platelet counts were preserved by platelet anesthesia during recirculation without platelet activation. These results suggest that FK633 inhibits the amplification loop by reducing the binding of fibrinogen to glycoprotein IIb/IIIa and platelet aggregation.

Restoration of sarcoplasmic reticulum protein level by thyroid hormone contributes to partial improvement of myocardial function, but not to glucose metabolism in an early failing heart.

OBJECTIVE: In heart failure, sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) activity is decreased, resulting in abnormal Ca(2+) handling and contractile dysfunction. We have previously reported that impaired glucose transporter (GLUT4) activity was an early indicator of progression of heart failure in pressure overload hypertrophied heart. This study was aimed to examine the contribution of both SERCA2 and glucose metabolism in pressure overload hypertrophied heart. Thyroid hormone, which is known to restore GLUT4 and/or SERCA2 function, was also tested. METHODS: Hypertrophied rat heart was created by abdominal aortic banding for 16 and 26 weeks. Then 20-40 microg/kg of 3,5,3'-triiodo-L-thyronine (T3) was administered subcutaneously daily for the last 4 weeks. Hypertrophied myocytes were created by the stimulation of H9c2(2-1) rat heart myoblasts with 2 micromol/L of isoproterenol for 3, 7 and 10 days. Left ventricle function of the hypertrophied rat hearts were measured in Langendorff perfusion. Myocardial protein levels of GLUT4 and SERCA2 in two models were analyzed by Western immunoblotting. Glucose and lactate concentration of cultured medium of myocytes were measured enzymatically to determine the efficacy of glycolysis. RESULTS: Diastolic function (tau) was significantly deteriorated in 16-week heart with significantly lower SERCA2 protein (89.3%) than control. In 26-week heart, both systolic and diastolic function (+dP/dt max, -dP/dt max and tau) was significantly deteriorated. This was associated with significant decrease in both GLUT4 and SERCA2 protein (84.8 and 91.6%, respectively). In cultured hypertrophied myocytes, glycolysis was shifted from aerobic to anaerobic during progression of hypertrophy. GLUT4 protein was significantly decreased at day 7 (45.6% of control). This led to a down-regulation of SERCA2 protein at day 10 (51.8% of control). Although there was no impact of T3 treatment on GLUT4, SERCA2 protein level was almost reversed with partial improvement of myocardial function. CONCLUSIONS: We conclude that impairment of both glucose metabolism and SERCA2 function were seen in an early heart failure. Thyroid hormone partially improved myocardial function with successful improvement of SERCA2 protein but no impact on GLUT4 protein expression in hypertrophied rat heart. Restoration of glucose metabolism is a critical step to avoid further progression of heart failure.

Evaluation of warm ischemia-reperfusion injury using heat shock protein in the rat liver.

We focused on heat shock protein 70 (HSP70) as a marker of viability in hepatic warm ischemia-reperfusion. Segmental hepatic warm ischemia was produced in rats for 15, 30, 60, 90, 120, or 180 min. Liver sections were evaluated at 30, 60, and 120 min of reperfusion. Expression of HSP70 and messenger RNA (mRNA), apoptosis, and apoptosis-associated genes such as Bcl-2 and Bax were studied. Expression of HSP70 and mRNA was augmented as warm ischemia was prolonged, but was markedly suppressed in livers with more than 120 min of ischemia. The highest accumulation of HSP70 was observed in the nucleus. In livers subjected to longer duration of warm ischemia, necrosis and apoptosis were evident and Bcl-2 mRNA expression and Bcl-2/Bax protein ratio were markedly diminished. Apoptosis may be related to the process of cellular injury induced by warm ischemia-reperfusion. Expression of HSP70 and the Bcl-2 family can be effective markers of viability in hepatic warm ischemia-reperfusion.

Relationship between postoperative recurrence and expression of cyclin E, p27, and Ki-67 in non-small cell lung cancer without lymph node metastases.

BACKGROUND: Cyclin E and p27 play pivotal roles in cancer development and progression. We investigated whether the prognosis in cases of non-small cell lung cancer without lymph node metastases that underwent complete resection could be associated with tissue expression of cyclin E, p27, and Ki-67. METHODS: Tumors from 62 patients at least 5 years after surgery were assessed by immunohistochemistry for expression of cyclin E, p27, and Ki-67. Disease-free survival (DFS) after surgery was used to evaluate disease prognosis. We also investigated the relationship between expression of these factors and postoperative recurrence. RESULTS: In non-small cell lung cancer, p27-negative expression and pT factor were significantly unfavorable prognostic factors in multivariate analysis. The DFS rate in cyclin E-positive expression was significantly lower than in cyclin E-negative expression. Similarly, p27-negative expression and high Ki-67 expression correlated with a shortened DFS rate. In combinations of expression of cyclin E and p27, the cyclin E-negative/p27-positive group had a significantly higher DFS rate than did the other groups. According to histological type, there were correlations between the risk of postoperative recurrence and expression of these three biological factors, especially in adenocarcinoma. CONCLUSION: By analyzing the expression of cyclin E, p27, and Ki-67 of tumor cells, it was possible to extract the patient group for whom closer follow-up and postoperative treatment is necessary to improve survival rate.

Proteasome inhibitor MG-132 enhances the expression of interleukin-6 in human umbilical vein endothelial cells: Involvement of MAP/ERK kinase.

Interleukin-6 (IL-6) is a multifunctional cytokine that plays an important role in inflammatory reactions. We have addressed the possible regulation of IL-6 expression by the ubiquitin-protease system in human umbilical vein endothelial cells. Cultured endothelial cells were treated with MG-132, a protease inhibitor, and the levels of IL-6 mRNA and protein were measured by reverse transcription-PCR and ELISA. MG-132 increased the expression of IL-6 mRNA and protein;and this effect was abolished by the pretreatment of the cells with U0126, an inhibitor of MAP or ERK kinases (MEK 1/2). MG-132 treatment was also found to enhance the level of phosphorylated MEK 1/2. Treatment of the cells with actinomycin D inhibited IL-6 expression in response to MG-132, suggesting the transcriptional upregulation of IL-6 under proteasomal inhibition. We conclude that a protease inhibitor MG-132 upregulates IL-6 expression in vascular endothelial cells, at least in part, through the activation of MEK 1/2.

Successfully repaired traumatic tracheal disruption and cardiac rupture with cardiopulmonary support.

A 19-year-old man suffering from dyspnea associated with tracheal and cardiac rupture from a traffic accident was found by bronchoscopy to have a 7.5 cm longitudinal tear in the membranous portion of the trachea. Right posterolateral thoracotomy was conducted and open ventilation through the left main bronchus initiated with standby cardiopulmonary bypass cannulation of the right femoral artery and vein. When oxygenation was poor, extracorporeal circulation was initiated through the cannulated artery and vein. Under the cardiopulmonary bypass, we safely repaired the tracheal laceration and cardiac rupture.