135 research outputs found

    Regulation of energy metabolism by interleukin-1 β, but not by interleukin-6, is mediated by nitric oxide in primary cultured rat hepatocytes

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    AbstractThe effects of inflammatory cytokines (interleukin-1 β, interleukin-6, and tumor necrosis factor-α) on energy metabolism were studied in primary cultured rat hepatocytes. Adenine nucleotide (ATP, ADP, and AMP) content, lactate production, the ketone body ratio (acetoacetate/β-hydroxybutyrate) reflecting the liver mitochondrial redox state (NAD+/NADH), and nitric oxide formation were measured. Insulin increased ATP content in hepatocytes and had a maximal effect after 8–12 h of culture. Both interleukin-1β and interleukin-6, but not tumor necrosis factor-α, significantly inhibited the ATP increase time- and dose-dependently. Interleukin-1β and interleukin-6 also stimulated lactate production. During the same period, interleukin-1 β but not interleukin-6 decreased the ketone body ratio. Furthermore, interleukin-1 β markedly stimulated nitric oxide formation in hepatocytes, and this increase was blocked by NG-monomethyl-L-arginine (a nitric oxide synthase inhibitor) and by interleukin-1 receptor antagonist. NG-monomethyl-l-arginine reversed inhibition of the ATP increase, decrease in the ketone body ratio, and increase in lactate production, which were induced by interleukin-lβ. Interleukin-1 receptor antagonist completely abolished all of the effects induced by interleukin-1 β. These results demonstrated that interleukin-1 β and interleukin-6 affect the insulin-induced energy metabolism in rat hepatocytes by different mechanisms. Specifically, interleukin-1 β inhibits ATP synthesis by causing the mitochondrial dysfunction, a process which may be mediated by nitric oxide

    Positive allosteric modulation of the calcium-sensing receptor by physiological concentrations of glucose

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    The calcium-sensing receptor (CaSR) is activated by various cations, cationic compounds, and amino acids. In the present study we investigated the effect of glucose on CaSR in HEK293 cells stably expressing human CaSR (HEK-CaSR cells). When glucose concentration in the buffer was raised from 3 to 25 mM, a rapid elevation of cytoplasmic Ca2+ concentration ([Ca2+](c)) was observed. This elevation was immediate and transient and was followed by a sustained decrease in [Ca2+](c). The effect of glucose was detected at a concentration of 4 mM and reached its maximum at 5 mM. 3-O-Methylglucose, a non-metabolizable analogue of glucose, reproduced the effect of glucose. Sucrose also induced an elevation of [Ca2+](c) in HEK-CaSR cells. Similarly, sucralose was nearly as effective as glucose in inducing elevation of [Ca2+](c). Glucose was not able to increase [Ca2+](c) in the absence of extracellular Ca2+. The effect of glucose on [Ca2+](c) was inhibited by NPS-2143, an allosteric inhibitor of CaSR. In addition, NPS-2143 also inhibited the [Ca2+](c) responses to sucralose and sucrose. Glucose as well as sucralose decreased cytoplasmic cAMP concentration in HEK-CaSR cells. The reduction of cAMP induced by glucose was blocked by pertussis toxin. Likewise, sucralose reduced [cAMP](c). Finally, glucose increased [Ca2+](c) in PT-r parathyroid cells and in Madin-Darby canine kidney cells, both of which express endogenous CaSR. These results indicate that glucose acts as a positive allosteric modulator of CaSR

    Ischemic and Bleeding Risk After Percutaneous Coronary Intervention in Patients With Prior Ischemic and Hemorrhagic Stroke

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    Background: Prior stroke is regarded as risk factor for bleeding after percutaneous coronary intervention (PCI). However, there is a paucity of data on detailed bleeding risk of patients with prior hemorrhagic and ischemic strokes after PCI. Methods and Results: In a pooled cohort of 19 475 patients from 3 Japanese PCI studies, we assessed the influence of prior hemorrhagic (n=285) or ischemic stroke (n=1773) relative to no-prior stroke (n=17 417) on ischemic and bleeding outcomes after PCI. Cumulative 3-year incidences of the co-primary bleeding end points of intracranial hemorrhage, non-intracranial global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries (GUSTO) moderate/severe bleeding, and the primary ischemic end point of ischemic stroke/myocardial infarction were higher in the prior hemorrhagic and ischemic stroke groups than in the no-prior stroke group (6.8%, 2.5%, and 1.3%, P<0.0001, 8.8%, 8.0%, and 6.0%, P=0.001, and 12.7%, 13.4%, and 7.5%, P<0.0001). After adjusting confounders, the excess risks of both prior hemorrhagic and ischemic strokes relative to no-prior stroke remained significant for intracranial hemorrhage (hazard ratio (HR) 4.44, 95% CI 2.64-7.01, P<0.0001, and HR 1.52, 95% CI 1.06-2.12, P=0.02), but not for non-intracranial bleeding (HR 1.18, 95% CI 0.76-1.73, P=0.44, and HR 0.94, 95% CI 0.78-1.13, P=0.53). The excess risks of both prior hemorrhagic and ischemic strokes relative to no-prior stroke remained significant for ischemic events mainly driven by the higher risk for ischemic stroke (HR 1.46, 95% CI 1.02-2.01, P=0.04, and HR 1.49, 95% CI 1.29-1.72, P<0.0001). Conclusions: Patients with prior hemorrhagic or ischemic stroke as compared with those with no-prior stroke had higher risk for intracranial hemorrhage and ischemic events, but not for non-intracranial bleeding after PCI

    Prognostic Impact of Baseline Hemoglobin Levels on Long-Term Thrombotic and Bleeding Events After Percutaneous Coronary Interventions

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    Background: Association of baseline hemoglobin levels with long-term adverse events after percutaneous coronary interventions has not been yet thoroughly defined. We aimed to assess the clinical impact of baseline hemoglobin on long-term ischemic and bleeding risk after percutaneous coronary intervention. Methods and Results: Using the pooled individual patient-level data from the 3 percutaneous coronary intervention studies, we categorized 19 288 patients into 4 groups: high-normal hemoglobin (≥14.0 g/dL; n=7555), low-normal hemoglobin (13.0-13.9 g/dL in men and 12.0-13.9 g/dL in women; n=5303), mild anemia (11.0-12.9 g/dL in men and 11.0-11.9 g/dL in women; n=4117), and moderate/severe anemia (<11.0 g/dL; n=2313). Median follow-up duration was 3 years. Low-normal hemoglobin, mild anemia, and moderate/severe anemia correlated with significant excess risk relative to high-normal hemoglobin for GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries Trial) moderate/severe bleeding, with adjusted hazard ratios of 1.22 (95% CI, 1.04-1.44), 1.73 (95% CI, 1.47-2.04), and 2.31 (95% CI, 1.92-2.78), respectively. Moderate/severe anemia also correlated with significant excess risk relative to high-normal hemoglobin for the ischemic composite end point of myocardial infarction/ischemic stroke (adjusted hazard ratio, 1.33; 95% CI, 1.11-1.60), whereas low-normal hemoglobin and mild anemia did not. However, the excess risk of low-normal hemoglobin, mild anemia, and moderate/severe anemia relative to high-normal hemoglobin remained significant for ischemic stroke and for mortality. Conclusions: Decreasing baseline hemoglobin correlated with incrementally higher long-term risk for major bleeding, ischemic stroke, and mortality after percutaneous coronary intervention. Even within normal range, lower baseline hemoglobin level correlated with higher ischemic and bleeding risk

    Apoptosis-dependent externalization and involvement in apoptotic cell clearance of DmCaBP1, an endoplasmic reticulum protein of Drosophila

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    To elucidate the actions of Draper, a receptor responsible for the phagocytic clearance of apoptotic cells in Drosophila, we isolated proteins that bind to the extracellular region of Draper using affinity chromatography. One of those proteins has been identified to be an uncharacterized protein called Drosophila melanogaster calcium-binding protein 1 (DmCaBP1). This protein containing the thioredoxin-like domain resided in the endoplasmic reticulum and seemed to be expressed ubiquitously throughout the development of Drosophila. DmCaBP1 was externalized without truncation after the induction of apoptosis somewhat prior to chromatin condensation and DNA cleavage in a manner dependent on the activity of caspases. A recombinant DmCaBP1 protein bound to both apoptotic cells and a hemocyte-derived cell line expressing Draper. Forced expression of DmCaBP1 at the cell surface made non-apoptotic cells susceptible to phagocytosis. Flies deficient in DmCaBP1 expression developed normally and showed Draper-mediated pruning of larval axons, but a defect in the phagocytosis of apoptotic cells in embryos was observed. Loss of Pretaporter, a previously identified ligand for Draper, did not cause a further decrease in the level of phagocytosis in DmCaBP1-lacking embryos. These results collectively suggest that the endoplasmic reticulum protein DmCaBP1 is externalized upon the induction of apoptosis and serves as a tethering molecule to connect apoptotic cells and phagocytes for effective phagocytosis to occur. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc

    Abscopal effect of radiation on lung metastases of hepatocellular carcinoma: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The abscopal effect is the effect of radiation therapy at a site distant to the area of irradiation. This is not a common event and has not been clearly defined, resulting in few reported cases in the literature. We discuss this phenomenon in a patient with hepatocellular carcinoma.</p> <p>Case presentation</p> <p>A 63-year-old Japanese man underwent extended right hepatic lobectomy for hepatocellular carcinoma. During his follow-up examination, a single lung metastasis and a single mediastinal lymph node metastasis were found. Trans-catheter arterial embolization was initially attempted to treat the mediastinal tumor, however this approach failed to take effect and carried risks of spinal artery embolism. External-beam irradiation, with a dose of 2.25 Gy per fraction, was performed using an antero-posterior parallel-opposed technique (total dose, 60.75 Gy). A computed tomography scan performed one month after starting radiotherapy showed a remarkable reduction of the mediastinal lymph node metastasis. In addition to this, we observed spontaneous shrinking of the lung metastasis, which was located in the right lower lobe and out of the radiation field. No chemotherapy was given during the period. There has been no recurrence of either the lung metastasis or the mediastinal lymph node metastasis during a follow-up 10 years after the radiotherapy.</p> <p>Conclusion</p> <p>We observed a rare abscopal effect in a site distant from the area of irradiation. Irradiation of the mediastinum resulted in tumor mass regression in the untreated lung tumor.</p

    Newly Diagnosed Atrial Fibrillation in Acute Myocardial Infarction

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    [Background] It remains controversial whether long‐term clinical impact of newly diagnosed atrial fibrillation (AF) in the acute phase of acute myocardial infarction (AMI) is different from that of prior AF diagnosed before the onset of AMI. [Methods and Results] The current study population from the CREDO‐Kyoto AMI (Coronary Revascularization Demonstrating Outcome Study in Kyoto Acute Myocardial Infarction) Registry Wave‐2 consisted of 6228 patients with AMI who underwent percutaneous coronary intervention. The baseline characteristics and long‐term clinical outcomes were compared according to AF status (newly diagnosed AF: N=489 [7.9%], prior AF: N=589 [9.5%], and no AF: N=5150 [82.7%]). Median follow‐up duration was 5.5 years. Patients with newly diagnosed AF and prior AF had similar baseline characteristics with higher risk profile than those with no AF including older age and more comorbidities. The cumulative 5‐year incidence of all‐cause death was higher in newly diagnosed AF and prior AF than no AF (38.8%, 40.7%, and 18.7%, P<0.001). The adjusted hazard ratios (HRs) for mortality of newly diagnosed AF and prior AF relative to no AF remained significant with similar magnitude (HR, 1.31; 95% CI, 1.12–1.54; P<0.001, and HR, 1.32; 95% CI, 1.14–1.52; P<0.001, respectively). The cumulative 5‐year incidence of stroke decreased in the order of newly diagnosed AF, prior AF and no AF (15.5%, 12.9%, and 6.3%, respectively, P<0.001). The higher adjusted HRs of both newly diagnosed AF and prior AF relative to no AF were significant for stroke, with a greater risk of newly diagnosed AF than that of prior AF (HR, 2.05; 95% CI, 1.56–2.69; P<0.001, and HR, 1.33; 95% CI, 1.00–1.78; P=0.048, respectively). The higher stroke risk of newly diagnosed AF compared with prior AF was largely driven by the greater risk within 30 days. The higher adjusted HRs of newly diagnosed AF and prior AF relative to no AF were significant for heart failure hospitalization (HR, 1.73; 95% CI, 1.35–2.22; P<0.001, and HR, 2.23; 95% CI, 1.82–2.74; P<0.001, respectively) and major bleeding (HR, 1.46; 95% CI, 1.23–1.73; P<0.001, and HR, 1.36; 95% CI, 1.15–1.60; P<0.001, respectively). [Conclusions] Newly diagnosed AF in AMI had risks for mortality, heart failure hospitalization, and major bleeding higher than no AF, and comparable to prior AF. The risk of newly diagnosed AF for stroke might be higher than that of prior AF

    Stent-Related Adverse Events as Related to Dual Antiplatelet Therapy in First- vs Second-Generation Drug-Eluting Stents

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    [Background] There are limited data on the long-term stent-related adverse events as related to the duration of dual antiplatelet therapy (DAPT) in second-generation (G2) drug-eluting stents (DES) compared with first-generation (G1) DES. [Objectives] This study sought to compare the long-term stent-related outcomes of G2-DES with those of G1-DES. [Methods] The study group consisted of 15, 009 patients who underwent their first coronary revascularization with DES from the CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Grafting) Registry Cohort-2 (first-generation drug-eluting stent [G1-DES] period; n = 5, 382) and Cohort-3 (second-generation drug eluting stent [G2-DES] period; n = 9, 627). The primary outcome measures were definite stent thrombosis (ST) and target vessel revascularization (TVR). [Results] The cumulative 5-year incidences of definite ST and TVR were significantly lower in the G2-DES group than in the G1-DES group (0.7% vs 1.4%; P < 0.001; and 16.2% vs 22.1%; P < 0.001, respectively). The lower adjusted risk of G2-DES relative to G1-DES for definite ST and TVR remained significant (HR: 0.53; 95% CI: 0.37-0.76; P < 0.001; and HR: 0.74; 95% CI: 0.68-0.81; P < 0.001, respectively). In the landmark analysis that was based on the DAPT status at 1 year, the lower adjusted risk of on-DAPT status relative to off-DAPT was significant for definite ST beyond 1 year in the G1-DES stratum (HR: 0.42; 95% CI: 0.24-0.76; P = 0.004) but not in the G2-DES stratum (HR: 0.66; 95% CI: 0.26-1.68; P = 0.38) (Pinteraction = 0.14). [Conclusions] G2-DES compared with G1-DES were associated with a significantly lower risk for stent-related adverse events, including definite ST and TVR. DAPT beyond 1 year was associated with a significantly lower risk for very late ST of G1-DES but not for that of G2-DES
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