Venous thromboembolism in hospitalized patients receiving chemotherapy for malignancies at Japanese community hospital: prospective observational study.

BACKGROUND: Although Asian population was recognized to have a lower risk of venous thromboembolism (VTE), its increasing prevalence and incidence remain unclear in patients with malignancies. We attempted to predict VTE development using activation markers of coagulation and fibrinolysis. METHODS: We enrolled patients with malignancy admitted to Tonan Hospital between April and December 2014 to receive a new-for-them chemotherapy regimen. All patients were examined for VTE by computed tomography and whole-leg compression ultrasonography before chemotherapy and three months later. We also examined plasma levels of thrombin-antithrombin complex (TAT) and plasmin α2-plasmin inhibitor complex (PIC) before chemotherapy. The cut off values of TAT and PIC were set at 2.1 ng/mL and 1.8 µg/mL, respectively. RESULTS: Of 97 patients, the majority (67%) had distant metastases. The most common malignancies were colorectal (26%), breast (23%), and stomach (19%) cancer. VTE was detected in 29 patients (31%); all were asymptomatic. VTE was newly developed in 12 patients in the three-month observation period, which means the incidence was 49 per 1000 person-years. Non-increased PIC with increased TAT was the only significant risk factor for both VTE prevalence and incidence in multivariate analysis, and the odds ratios were 3.0 (95% confidence interval, 1.1-8.2; P = 0.034) and 9.4 (95% confidence interval, 1.7-51.9; P = 0.011), respectively. CONCLUSIONS: The prevalence and incidence of VTE were high in hospitalized Japanese patients receiving chemotherapy for malignancies. Non-increased PIC with increased levels of TAT may be an independent risk factor for VTE development.

High-sensitive troponin T assay can predict anthracycline- and trastuzumab-induced cardiotoxicity in breast cancer patients.

BACKGROUND: Trastuzumab following anthracycline causes cardiotoxicity in up to 28% of patients. Although the cardiotoxicity is often irreversible once cardiac dysfunction is detected, the early predictor has not been established yet. METHODS: We prospectively observed breast cancer patients treated with anthracycline or trastuzumab at Tonan Hospital. All patients underwent echocardiography and blood sampling at baseline, and every three months during chemotherapy. Cardiotoxicity was defined as a decline in left ventricular ejection fraction >10% points. RESULTS: Of 40 patients, 34 patients (85%) were treated with anthracycline (epirubicin), 18 (45%) with trastuzumab, and 12 (30%) with both agents. Cardiotoxicity was observed in four patients (10%), who were all treated with both agents. The absolute levels of high-sensitive troponin T (hs-TnT) were increased in all four patients with cardiotoxicity, and all the highest points were observed before or at the time of detection of cardiotoxicity. The highest level of hs-TnT was not significantly different in patients with and without cardiotoxicity. "Hs-TnT increment from baseline to the highest value" and "hs-TnT integration value above baseline" were significantly greater in patients with cardiotoxicity (0.039 vs. 0.007 ng/mL, P = 0.046, 0.113 vs. 0.022 ng months/mL, P = 0.013, respectively). The integration value had 100% sensitivity and specificity with a cutoff level at 0.070 ng months/mL. CONCLUSIONS: Hs-TnT assay may be able to predict anthracycline- and trastuzumab-induced cardiotoxicity in breast cancer patients, and the hs-TnT increment or hs-TnT integration value above baseline was more reliable than the absolute value.

Sensitive and specific PCR systems for detection of both Chinese and Japanese severe fever with thrombocytopenia syndrome virus strains and prediction of patient survival based on viral load.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high case fatality risk and is caused by the SFTS virus (SFTSV). A retrospective study conducted after the first identification of an SFTS patient in Japan revealed that SFTS is endemic to the region, and the virus exists indigenously in Japan. Since the nucleotide sequence of Japanese SFTSV strains contains considerable differences compared with that of Chinese strains, there is an urgent need to establish a sensitive and specific method capable of detecting the Chinese and Japanese strains of SFTSV. A conventional one-step reverse transcription-PCR (RT-PCR) (cvPCR) method and a quantitative one-step RT-PCR (qPCR) method were developed to detect the SFTSV genome. Both cvPCR and qPCR detected a Chinese SFTSV strain. Forty-one of 108 Japanese patients suspected of having SFTS showed a positive reaction by cvPCR. The results from the samples of 108 Japanese patients determined by the qPCR method were in almost complete agreement with those determined by cvPCR. The analyses of the viral copy number level in the patient blood samples at the acute phase determined by qPCR in association with the patient outcome confirmed that the SFTSV RNA load in the blood of the nonsurviving patients was significantly higher than that of the surviving patients. Therefore, the cvPCR and qPCR methods developed in this study can provide a powerful means for diagnosing SFTS. In addition, the detection of the SFTSV genome level by qPCR in the blood of the patients at the acute phase may serve as an indicator to predict the outcome of SFTS.

Constitutive glycogen synthase kinase-3alpha/beta activity protects against chronic beta-adrenergic remodelling of the heart.

AIMS: Glycogen synthase kinase 3 (GSK-3) signalling is implicated in the growth of the heart during development and in response to stress. However, its precise role remains unclear. We set out to characterize developmental growth and response to chronic isoproterenol (ISO) stress in knockin (KI) mice lacking the critical N-terminal serines, 21 of GSK-3alpha and 9 of GSK-3beta respectively, required for inactivation by upstream kinases. METHODS AND RESULTS: Between 5 and 15 weeks, KI mice grew more rapidly, but normalized heart weight and contractile performance were similar to wild-type (WT) mice. Isolated hearts of both genotypes responded comparably to acute ISO infusion with increases in heart rate and contractility. In WT mice, chronic subcutaneous ISO infusion over 14 days resulted in cardiac hypertrophy, interstitial fibrosis, and impaired contractility, accompanied by foetal gene reactivation. These effects were all significantly attenuated in KI mice. Indeed, ISO-treated KI hearts demonstrated reversible physiological remodelling traits with increased stroke volume and a preserved contractile response to acute adrenergic stimulation. Furthermore, simultaneous pharmacological inhibition of GSK-3 in KI mice treated with chronic subcutaneous ISO recapitulated the adverse remodelling phenotype seen in WT hearts. CONCLUSION: Expression of inactivation-resistant GSK-3alpha/beta does not affect eutrophic myocardial growth but protects against pathological hypertrophy induced by chronic adrenergic stimulation, maintaining cardiac function and attenuating interstitial fibrosis. Accordingly, strategies to prevent phosphorylation of Ser-21/9, and consequent inactivation of GSK-3alpha/beta, may enable a sustained cardiac response to chronic beta-agonist stimulation while preventing pathological remodelling.

Glycogen synthase kinase-3 inactivation is not required for ischemic preconditioning or postconditioning in the mouse.

The inactivation of glycogen synthase kinase-3beta (GSK-3beta) is proposed as the event integrating protective pathways initiated by preconditioning and other interventions. The inactivation of GSK-3 is thought to decrease the probability of opening of the mitochondrial permeability transition pore. The aim of this study was to verify the role of GSK-3 using a targeted mouse line lacking the critical N-terminal serine within GSK-3beta (Ser9) and the highly homologous GSK-3alpha (Ser21), which when phosphorylated results in kinase inactivation. Postconditioning with 10 cycles of 5 seconds of reperfusion/5 seconds of ischemia and preconditioning with 6 cycles of 4 minutes of ischemia/6 minutes of reperfusion, similarly reduced infarction of the isolated perfused mouse heart in response to 30 minutes of global ischemia and 120 minutes of reperfusion. Preconditioning caused noticeable inactivating phosphorylation of GSK-3. However, both preconditioning and postconditioning still protected hearts of homozygous GSK-3 double knockin mice. Moreover, direct pharmacological inhibition of GSK-3 catalytic activity with structurally diverse inhibitors before or after ischemia failed to recapitulate conditioning protection. Nonetheless, cyclosporin A, a direct mitochondrial permeability transition pore inhibitor, reduced infarction in hearts from both wild-type and homozygous GSK-3 double knockin mice. Furthermore, in adult cardiac myocytes from GSK-3 double knockin mice, insulin exposure was still as effective as cyclosporin A in delaying mitochondrial permeability transition pore opening. Our results, which include a novel genetic approach, suggest that the inhibition of GSK-3 is unlikely to be the key determinant of cardioprotective signaling in either preconditioning or postconditioning in the mouse.

The role of RIP2 in p38 MAPK activation in the stressed heart.

The activation of p38 MAPK by dual phosphorylation aggravates myocardial ischemic injury and depresses cardiac contractile function. SB203580, an ATP-competitive inhibitor of p38 MAPK and other kinases, prevents this dual phosphorylation during ischemia. Studies in non-cardiac tissue have shown receptor-interacting protein 2 (RIP2) lies upstream of p38 MAPK, is SB203580-sensitive and ischemia-responsive, and aggravates ischemic injury. We therefore examined the RIP2-p38 MAPK signaling axis in the heart. Adenovirus-driven expression of wild-type RIP2 in adult rat ventricular myocytes caused robust, SB203580-sensitive dual phosphorylation of p38 MAPK associated with activation of p38 MAPK kinases MKK3, MKK4, and MKK6. The effect of SB203580 was recapitulated by unrelated inhibitors of RIP2 or the downstream MAPK kinase kinase, TAK1. However, overexpression of wild-type, kinase-dead, caspase recruitment domain-deleted, or kinase-dead and caspase recruitment domain-deleted forms of RIP2 had no effect on the activating dual phosphorylation of p38 MAPK during simulated ischemia. Similarly, p38 MAPK activation and myocardial infarction size in response to true ischemia did not differ between hearts from wild-type and RIP2 null mice. However, both p38 MAPK activation and the contractile depression caused by the endotoxin component muramyl dipeptide were attenuated by SB203580 and in RIP2 null hearts. Although RIP2 can cause myocardial p38 MAPK dual phosphorylation in the heart under some circumstances, it is not responsible for the SB203580-sensitive pattern of activation during ischemia.

Intracardiac fibroblasts, but not bone marrow derived cells, are the origin of myofibroblasts in myocardial infarct repair.

UNLABELLED: Origin of myofibroblasts in infarcted myocardium was examined by using rats in which bone marrow of green fluorescent protein (GFP)-transgenic mice had been transplanted. GFP was not detected in myofibroblasts at either 3 or 7 days after infarction, suggesting that proliferating myofibroblasts in infarcted myocardium are derived from resident fibroblasts rather than circulating precursor cells of bone marrow origin. BACKGROUND: Myofibroblasts play important roles in the repair process of myocardial infarct, and their origin has been assumed to be interstitial fibroblasts in the heart. However, bone marrow-derived myofibroblasts have recently been identified in pathological fibrosis in extracardiac tissues. In this study, we aimed to determine whether some of the myofibroblasts in infarcted myocardium are derived from circulating precursor cells of bone marrow origin. METHODS AND RESULTS: Bone marrow (BM) of GFP-transgenic mice was transplanted into nude rats, and their coronary arteries were occluded for 60 min and reperfused for 3 or 7 days. Non-BM-transplanted rats served as controls. At 3 days after infarction, some endothelial cells were GFP-positive, indicating that they were of bone marrow origin. Predominant cells in infarcted regions were macrophages and neutrophils, and there were only a small number of vimentin-positive cells and fewer myofibroblasts, both of which were GFP-negative. At 7 days after infarction, there were numerous myofibroblasts in granulation tissue replacing necrotic myocytes, and none of them showed GFP signals, whereas some cells were positive for both GFP and vimentin. Appearance of myofibroblasts and extent of the infarct repair in BM-transplanted and those in non-transplanted rats were similar. CONCLUSIONS: The findings in this study suggest that proliferating myofibroblasts in infarcted myocardium are derived from resident fibroblasts rather than circulating precursor cells of bone marrow origin.

Ischemic preconditioning activates AMPK in a PKC-dependent manner and induces GLUT4 up-regulation in the late phase of cardioprotection.

OBJECTIVE: The aim of this study was to determine the role of AMP-activated protein kinase (AMPK) and its link to protein kinase C (PKC) in the late phase of cardioprotection afforded by ischemic preconditioning (PC) against myocardial stunning. METHODS AND RESULTS: Rabbits were instrumented with a balloon occluder around a coronary artery and with a Doppler sensor to monitor the thickening fraction (TF). Conscious rabbits underwent five cycles of 5-min ischemia/5-min reperfusion (I/R) on 2 consecutive days (days 1 and 2). Reduction of TF after I/R was significantly less and recovery of TF was faster on day 2, indicating a late PC effect. PC provoked translocation of PKC- from the cytosol to the membrane and significantly increased AMPK activity by 100% immediately after PC. The mRNA level of GLUT4, a glucose transporter, was elevated by 150% at 3 h after PC, and the total protein level of GLUT4 was increased by 107% at 24 h after PC. The level of sarcolemmal GLUT4 protein after I/R on day 2 was 41% higher than its level after I/R on day 1. AMPK activation and up-regulation of GLUT4 by PC were abrogated by pre-treatment with PKC inhibitors. CONCLUSION: PC activated AMPK and up-regulated GLUT4 expression in a PKC-dependent manner. This GLUT4 up-regulation at 24 h after PC may contribute to attenuation of myocardial stunning.

Granulocyte colony stimulating factor/macrophage colony stimulating factor improves postinfarct ventricular function by suppression of border zone remodelling in rats.

1. The aim of the present study was to examine the effects of mobilization of bone marrow cells by granulocyte colony stimulating factor (G-CSF) and macrophage colony stimulating factor (M-CSF) on ventricular function after myocardial infarction (MI). 2. After ligation of the left coronary artery, rats were divided into a vehicle control group (MI group) and a CSF-treated group (MI-CSF group). Rats in the MI-CSF group received a combination of G-CSF (50 microg/kg per day) and M-CSF (10(6) IU/kg per day) for 5 days after MI. Two weeks after MI, hearts were isolated and perfused with a Krebs' buffer and their functional responses to step-wise elevation of left ventricular end-diastolic pressure (LVEDP) were assessed. In histological analysis, proliferating cells and bone marrow-derived cells were identified by antibodies against Ki-67 and c-kit and organization of collagen was examined by picrosirius red staining. The mRNA levels of transforming growth factor (TGF)-beta(1), collagen type I and collagen type III were measured by quantitative reverse transcription-polymerase chain reaction. 3. Numbers of Ki-67- and c-kit-positive cells in the infarct border zone after MI were increased by CSF treatment, but few of those cells were stained by anti-alpha-sarcomeric actin. The levels in mRNA of TGF-beta1 and collagen type I in the infarct border zone were higher in the CSF-treated group compared with the MI group. Although CSF treatment did not reduce ventricular hypertrophy or infarct size at 2 weeks after MI, it did significantly improved the response of left ventricular developed pressure to step-wise elevation of LVEDP. This effect was mimicked by treatment with M-CSF alone. The functional improvement by CSF treatment was correlated with suppression of enlargement of the infarct-non-infarct border associated with infarct expansion. Collagen fibres in the border zone were thicker and orientated more orderly in the CSF-treated group than in the untreated group. 4. The results suggest that G-CSF/M-CSF treatment improves contractile function of the ventricle after infarction, presumably by acceleration of infarct repair and suppression of remodelling in the border zone.

Does enhanced expression of the Na+-Ca2+ exchanger increase myocardial vulnerability to ischemia/reperfusion injury in rabbit hearts?

Reverse-mode activation of the Na+-Ca2+ exchanger (NCX) at the time of reperfusion following ischemia contributes to Ca2+ overload and cardiomyocyte injury. The aim of the present study was to determine whether increased NCX in the myocardium that survived after infarction enhances its vulnerability to ischemia/reperfusion injury. Rabbits were divided into post-MI and sham groups and underwent ligation of the left circumflex coronary artery and sham operation, respectively. Two weeks later, hearts were isolated and perfused with crystalloid in the Langendorff mode with monitoring of left ventricular (LV) pressure. NCX level in the myocardium was determined by Western blotting. Myocardial stunning was induced by 5 episodes of 5-min global ischemia/5-min reperfusion. Using separate groups of hearts, myocardial infarction was induced by 30-min global ischemia/2-h reperfusion with or without treatment with 0.3 microM KB-R7943, a reverse-mode selective blocker of NCX. Heart weight-to-body weight ratio was 20% larger and NCX protein level was 60% higher in the post-MI group than in the sham group. However, there were no significant differences between severities of myocardial stunning after the repetitive ischemia/ reperfusion (18 +/- 7 vs. 25 +/- 2% reduction in LV developed pressure) and between infarct sizes after 30-min ischemia (59.1 +/- 4.1 vs. 63.0 +/- 4.5% of risk area) in the post-MI and sham groups. KB-R7943 limited infarct size in the post-MI group by 53%, and the extent of this protection was not different from that we have reported for hearts without previous infarcts (i.e. 45% reduction of infarct size). These results suggest that enhanced NCX expression does not necessarily increase myocardial vulnerability to myocardial stunning and infarction.

Blockade of angiotensin II type 1 receptors suppressed free radical production and preserved coronary endothelial function in the rabbit heart after myocardial infarction.

The hypothesis that blockade of angiotensin II type 1 (AT1) receptors after myocardial infarction prevents coronary endothelial vasomotor dysfunction by suppressing oxygen free radical production was examined. Rabbits underwent coronary ligation or a sham operation with or without infusion of valsartan, an AT 1 receptor blocker. Two weeks after the operation, the heart was isolated from each rabbit and perfused with buffer in the Langendorff mode, and coronary flow responses to acetylcholine and sodium nitroprusside were assessed. The ratio of heart weight to body weight and the lipid peroxide level in the myocardium were increased by 30 and 50%, respectively, 2 weeks after infarction. The coronary flow response to acetylcholine (10(-8) to 10(-5) M) was reduced by 50% in the hearts with infarction compared with the sham controls, although coronary flow responses to sodium nitroprusside were similar. The coronary flow response to acetylcholine in the hearts with infarction was restored by concurrent infusion of N -2-mercaptopropionyl-glycine, a free radical scavenger. Valsartan (10 mg/kg/d) infused after infarction prevented both ventricular remodeling and elevation of the tissue lipid peroxide level and preserved coronary flow response to acetylcholine. In conclusion, long-term AT1 receptor blockade after infarction protects the coronary arteries from endothelial vasomotor dysfunction through suppression of free radical production.