Non-clinical studies indicating lack of interactions between iron/calcium ions and linzagolix, an orally available GnRH antagonist.

Linzagolix is an orally available gonadotropin-releasing hormone antagonist used to treat sex-hormone-dependent diseases in women. This study aimed to investigate drug-drug interactions between linzagolix and iron/calcium ions in the intended clinical setting by conducting pharmacokinetic studies in vitro and in rats.Insoluble precipitate formation with metal ions was evaluated by measuring linzagolix concentrations in four types of bio-relevant dissolution media (fasted/fed state simulated gastric fluid and fasted/fed state simulated gastric fluid version 2), and chelate complex formation with metal ions was evaluated by release of linzagolix from a cellulose membrane sac. In these in vitro studies, linzagolix showed no potential for insoluble precipitate formation under fasted/fed conditions and no chelate complex formation in the presence of metal ions.In rats, the plasma concentration-time profiles of linzagolix and iron ion were similar regardless of whether they were administered with or without ferrous sulphate and linzagolix choline at clinically relevant doses. Thus, linzagolix and iron ion had no effect on each other's absorption in vivo.In conclusion, linzagolix is unlikely to cause clinically relevant drug-drug interactions by chelating metal ions according to the results of in vitro and in vivo studies.

Giant aneurysm of left circumflex artery branch with fistula to the coronary sinus: a case report.

BACKGROUND: Aneurysm of a coronary artery branch with a fistula is extremely rare. Here, we present a case of giant aneurysm of the left circumflex artery branch with a fistula to the coronary sinus treated successfully with aneurysmectomy. CASE PRESENTATION: A 58-year-old woman was referred to our hospital due to an abnormal pericardial mass found by multidetector computed tomography. Imaging examination revealed a dilated left circumflex artery branch with a 30-mm aneurysm. Coronary angiography confirmed a left circumflex artery branch aneurysm with a fistula to the coronary sinus. As percutaneous occlusion of the aneurysm by catheterization was considered unsuccessful, the aneurysm was resected, and the fistula was occluded surgically with excellent outcome. Pathological examination suggested that congenital factors may have contributed to the development of the aneurysm. Computed tomography showed no recurrence of the aneurysm at 1-year postoperative follow-up. CONCLUSIONS: We presented a case of giant aneurysm of the left circumflex artery branch with a fistula to the coronary sinus. This is the first report of the combination of a giant coronary artery branch aneurysm with a fistula to the coronary sinus. Surgical aneurysmectomy should be considered in such cases to avoid fatal aneurysmal complications.

[Intraoperative Pulmonary Artery Rupture Induced by a Pulmonary Artery Catheter].

We herein present a case of massive intratracheal hemorrhage due to pulmonary artery catheter (PAC) use during triple valve surgery. A 75-year-old woman underwent biological aortic valve replacement along with mitral and tricuspid valve annuloplasty. Operative procedures were uneventful. Shortly after weaning from cardiopulmonary bypass, massive blood and froth filled the endotracheal tube. As her blood pressure and arterial oxygen saturation dropped, extracorporeal membrane oxygenation(ECMO) support through the right femoral artery and vein was promptly initiated. After the tip of the PAC was identified in the right pulmonary artery by chest Xray, an endobronchial blocker was used to protect the opposite lung. After clinical stability was achieved, she underwent pulmonary artery angiography and subsequent successful transcatheter embolization. Right heart unloading using ECMO and transcatheter embolization might have played key roles in the management of intraoperative pulmonary artery rupture.

[True Ascending Aortic Aneurysm Late after Total Arch Replacement].

An aortic aneurysm was incidentally diagnosed in a 75-year-old woman during a thorough examination for other diseases. She had a history of total arch replacement( TAR) for aortic arch aneurysm 17 years previously. Contrast-enhanced computed tomography( CT) revealed a proximal aortic aneurysm with a maximum diameter of 67 mm protruding to the lateral side. She was treated by elective ascending aortic replacement. The resected aneurysm was not a pseudoaneurysm, but a true aneurysm. The etiology of this aneurysm might be long-term hemodynamic stress from the left ventricle and inadequate blood pressure control in addition to the anatomical position of the proximal residual aorta after first surgery. Therefore, to prevent aneurysm formation, it is important to replace the ascending aorta as proximally as possible at first surgery and to continue strict postoperative blood pressure control.

Quantitative Evaluation of Reactivity and Toxicity of Acyl Glucuronides by [35S]Cysteine Trapping.

Acyl glucuronides (AGs) are reactive metabolites of carboxylic acid-containing drugs, which are associated with idiosyncratic toxicity (IDT) such as anaphylaxis, drug-induced liver injury, and so on. In this study, we developed a new in vitro approach for the quantitative assessment of the reactivity of AGs and their toxicity risk. Thirteen test drugs were incubated with human liver microsomes and uridine 5'-diphospho-glucuronic acid in the presence of cysteine (Cys) as a trapping agent. Both acylation and glycation Cys adducts formed from the AGs of the test drugs and were analyzed by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry. Acylation Cys adduct formation can closely reflect the reactivity of AGs to predict their IDT risk. Subsequently, we performed a quantitative trapping assay using radiometric analysis, with [35S]-labeled Cys ([35S]Cys) as the trapping agent, and the results showed that the test drugs associated with IDT resulted in a high product formation of [35S]Cys adducts. In conclusion, this approach can be used for the easy and quantitative evaluation of the reactivity of AGs without the need for authentic AG standards and to screen the potential IDT of new chemical entities during the early drug discovery phase.

Long-term Effect of Enlargement of a Ventricular Septal Defect in the Rastelli Procedure.

We investigated the effect of ventricular septal defect (VSD) enlargement on long-term surgical results, late arrhythmia, and left ventricular (LV) function in the Rastelli procedure for D-transposition of the great arteries with LV outflow tract obstruction (LVOTO). From 1979 to 2001, 74 patients (D-transposition of the great arteries, n = 56; double outlet right ventricle, n = 18) underwent the Rastelli procedure. In group A, 46 patients underwent the Rastelli procedure with VSD enlargement, and in group B, 28 patients underwent the Rastelli procedure without enlargement. There were no hospital deaths. Actuarial survival at 20 years was 80% in group A and 91% in group B (P = 0.50). Freedom from reoperations at 20 years was 40.1% in group A and 52.0% in group B. Reoperations for LVOTO were performed in 2 patients in both groups. In postoperative catheterization, LV ejection fraction in group A was 57.1% ± 8.7% vs 57.2% ± 8.1% in group B (P = 0.97); LV end-diastolic volume, 150.0% ± 47.2% vs 142.0% ± 36.9% of the normal volume (P = 0.97). In long-term postoperative echocardiography, the pressure gradient of the LV to the aorta was 12.0 ± 12.8 vs 17.7 ± 26.0 mm Hg in groups A and B (P = 0.31). There were no differences between the groups regarding basal rhythms, anti-arrhythmic agents, and pacemaker implantation rate. VSD enlargement in the Rastelli procedure can be safely performed without early mortality and with long-term low mortality and morbidity regarding arrhythmia, LV function, and reoperation for late LVOTO. VSD enlargement should be considered as an option for avoiding long-term LVOTO.

[Hybrid Coronary Revascularization of Minimally Invasive Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention in a Patient with Left Main Coronary Stenosis].

We report a successful case of hybrid coronary revascularization of minimally invasive coronary artery bypass grafting( MICS-CABG) and percutaneous coronary intervention(PCI). The patient was a 78-year-old man with angina pectoris due to left main trunk (LMT) lesion, and had a history of repeated PCI to the left anterior descending artery (LAD) and the left circumflex artery (LCX) for angina pectoris. He presented with a chest pain on effort in June, 2015. A coronary angiogram showed a severe stenosis in the LMT extending to LAD and LCX. We performed hybrid therapy of CABG to LAD, and PCI to LMT and the proximal portion of LCX because the lesion was technically and suitable for PCI. CABG to LAD was performed via left mini thoracotomy using the left inter mammary artery (LIMA). LIMA was harvested under 3-dimentional endoscope. On the 5th post-operative day, PCI was performed to LMT and LCX. The postoperative course was uneventful and he was discharged on the 11th post-operative day. This case suggests that hybrid coronary revascularization is less invasive and feasible for selected patients with multi-vessel disease.

[Suspended Ventricular Septal Defect Closure Due to Heparin Resistance;Report of a Case].

We present a case of heparin resistance whereby open heart surgery was discontinued. A 53-year-old woman who was diagnosed with ventricular septal defect and atrial septal defect was scheduled for intracardiac repair. However, after intravenous heparin (400 U kg-1) supplementation, the activated clotting time (ACT) increased only to seconds. The operation was discontinued because the addition of heparin( 200 U kg-1) did not show sufficient prolongation of ACT, fully indicative of heparin resistance. Additional antithrombin III concentrate was also ineffective. Postoperative study of the administration of heparin in vitro to the patient's serum showed the probability of transient heparin resistance arising from the stress of surgery.

Transcatheter aortic valve implantation in a patient with aplastic anemia.

Aplastic anemia is a syndrome involving pancytopenia caused by bone marrow insufficiency. Pancytopenia increases the surgical risk of bleeding and infection. Here, we report a successful transcatheter aortic valve implantation (TAVI) in a patient with aplastic anemia. The patient was a 76-year-old woman who was admitted to our hospital with syncope. Laboratory testing showed pancytopenia, and echocardiography revealed severe aortic valve stenosis. Although the log.EuroSCORE and STS Score were not overly high, because of the presence of pancytopenia, surgical aortic valve replacement was considered too high risk, making her a candidate for TAVI. In this case, the patient's pancytopenia was so severe that even TAVI without preparation was considered high risk. In light of this, we carried out a two-day preoperative administration of granulocyte colony-stimulating factor and transfused packed red blood cells and platelet concentrates. TAVI was performed via the left femoral artery using the cut-down procedure under general anesthesia. The postoperative course was uneventful, and she was discharged on the sixth postoperative day. With adequate preoperative preparation, TAVI may be performed safely in high-risk patients with hematologic disorders. .

Aortic root replacement for annuloaortic ectasia with a single coronary artery.

A single coronary artery, arising from the left sinus of Valsalva, associated with a bicuspid aortic valve and annuloaortic ectasia, is very rare. We report on a surgical case of bicuspid aortic valve regurgitation, annuloaortic ectasia, and dilation of the ascending aorta to the aortic arch in a patient with a single coronary artery. We successfully performed aortic root replacement with reimplantation of the single coronary artery and total arch replacement. The reimplantation of the coronary orifice required particular attention. Postoperative CT demonstrated the expected contours from the aortic annulus to the aortic arch with a patent implanted coronary artery.

[Midterm Outcomes of Root Replacement Using Homograft for Aortic Valve Infective Endocarditis].

From August 2003 to June 2013, 9 patients with aortic valve endocarditis underwent aortic root replacement using homografts which were harvested and preserved in our institute. The median patient age was 62 years (range 46~84) and 5 patients were men. Four cases were prosthetic valve infections. The in-hospital mortality was 0%. In 8 of 9 cases were evaluated on midterm outcomes. At a median of 52 months (range 19~156), overall survival was 100%, freedom from cardiovascular events was 87.5%. The peak aortic pressure gradient was 9.04 ± 4.2 mmHg. Aortic regurgitation was less than 2 of 4 in all cases.

Regulation of cytochrome b5 expression by miR-223 in human liver: effects on cytochrome P450 activities.

PURPOSE: Cytochrome b5 (b5) is a hemoprotein that transfers electrons to several enzymes to fulfill functions in fatty acid desaturation, methemoglobin reduction, steroidogenesis, and drug metabolism. Despite the importance of b5, the regulation of b5 expression in human liver remains largely unknown. We investigated whether microRNA (miRNA) might be involved in the regulation of human b5. METHODS: Twenty-four human liver specimens were used for correlation analysis. In silico analysis and luciferase assay were performed to determine whether the predicted miRNAs functionally target to b5. The miR-223 was overexpressed into HepG2 cells infected with adenovirus expressing human cytochrome P450. RESULTS: In human livers, the b5 protein levels were not positively correlated with the b5 mRNA levels, and miR-223 levels were inversely correlated with the b5 mRNA levels or the translational efficiencies. The luciferase assay showed that miR-223 functionally binds to the element in the 3'-untranslated region of b5 mRNA. The overexpression of miR-223 significantly reduced the endogenous b5 protein level and the mRNA stability in HepG2 cells. Moreover, the overexpression of miR-223 significantly reduced CYP3A4-catalyzed testosterone 6ß-hydroxylation activity and CYP2E1-catalyzed chlorzoxazone 6-hydroxylase activity but not CYP1A2-catalyzed 7-ethoxyresorufin O-deethylase activity. CONCLUSIONS: miR-223 down-regulates b5 expression in the human liver, modulating P450 activities.

Hepatoprotective effect of tamoxifen on steatosis and non-alcoholic steatohepatitis in mouse models.

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic lipid accumulation that starts with steatosis and progresses to non-alcoholic steatohepatitis (NASH). Recently, the number of patients with such liver diseases has increased, but the understanding of the fundamental mechanisms and appropriate therapies are lacking. Tamoxifen (TAM) is a selective estrogen receptor modulator. We previously reported that TAM plays a protective role against drug-induced and chemical-induced acute liver injuries. However, the effects of TAM on chronic liver injury, including steatosis and NASH, remain to be addressed. We first found that the administration of TAM to mouse models of steatosis and NASH significantly decreased the plasma ALT and AST levels. The administration of TAM decreased the accumulated fat and inflammation in the livers in both mouse models. In addition, we observed decreased hepatic mRNA levels of triglyceride synthesis, acyl-CoA: diacylglycerol acyltransferase 2 (DGAT2), proinflammatory cytokines, tumor necrosis factor (TNF) α, and chemokines, monocyte chemoattractant protein (MCP) -1. TAM increased the extracellular signal-regulated kinase (ERK) phosphorylation, which is related to the proliferation and regeneration of liver and to decreased DGAT2 gene expression. Furthermore, a decrease in eukaryotic translational initiation factor (eIF2α), which is involved in apoptosis, was observed in both models. These findings suggest that TAM treatment exerts a hepatoprotective effect against steatosis and NASH, presumably via up-regulation of the ERK pathways and attenuation of eIF2α activation. These pathways represent a potential therapeutic target for steatosis and NASH in drug development.

Mechanisms of the hepatoprotective effects of tamoxifen against drug-induced and chemical-induced acute liver injuries.

Although estrogen receptor (ER)α agonists, such as estradiol and ethinylestradiol (EE2), cause cholestasis in mice, they also reduce the degree of liver injury caused by hepatotoxicants as well as ischemia-reperfusion. The functional mechanisms of ERα have yet to be elucidated in drug-induced or chemical-induced liver injury. The present study investigated the effects of an ERα agonist, selective ER modulators (SERMs) and an ER antagonist on drug-induced and chemical-induced liver injuries caused by acetaminophen, bromobenzene, diclofenac, and thioacetamide (TA). We observed hepatoprotective effects of EE2, tamoxifen (TAM) and raloxifene pretreatment in female mice that were exposed to a variety of hepatotoxic compounds. In contrast, the ER antagonist did not show any hepatoprotective effects. DNA microarray analyses suggested that monocyte to macrophage differentiation-associated 2 (Mmd2) protein, which has an unknown function, is commonly increased by TAM and RAL pretreatment, but not by pretreatment with the ER antagonist. In ERα-knockout mice, the hepatoprotective effects of TAM and the increased expression of Mmd2 mRNA were not observed in TA-induced liver injury. To investigate the function of Mmd2, the expression level of Mmd2 mRNA was significantly knocked down to approximately 30% in mice by injection of siRNA for Mmd2 (siMmd2). Mmd2 knockdown resulted in a reduction of the protective effects of TAM on TA-induced liver injury in mice. This is the first report of the involvement of ERα in drug-induced or chemical-induced liver injury. Upregulation of Mmd2 protein in the liver was suggested as the mechanism of the hepatoprotective effects of EE2 and SERMs.

Stimulation of human monocytic THP-1 cells by metabolic activation of hepatotoxic drugs.

Drug-induced liver injury (DILI) is thought to be involved in the participation of drugs that either directly affect the cell viability or elicit an immune response. However, there is limited information about the immune responses induced by drugs, including those drugs that are metabolically activated. In this study, we constructed an in vitro assay system to assess the involvement of immune-related factors induced by metabolic activation of drugs. To investigate whether CYP3A4-mediated metabolism of 10 hepatotoxic drugs is associated with immune-related responses, human monocytic leukemia THP-1 cells were co-incubated with CYP3A4 Supersomes. Cluster of differentiation (CD) 86 and CD54 expression levels on THP-1 cells were upregulated by treatment with albendazole and amiodarone (AMD), respectively, in the presence of CYP3A4. Additionally, N-desethylamiodarone (DEA), a major metabolite of AMD, upregulated the CD54 expression of THP-1 cells with CYP3A4. The release of interleukin (IL)-8 and tumor necrosis factor (TNF) α from THP-1 cells was significantly increased by the treatment of AMD or DEA with CYP3A4. Similarly, IL-8 and TNFα were also upregulated by the treatment of AMD and DEA with human liver microsomes, but were inhibited by adding ketoconazole to the cell culture. In this study, we first report that albendazole, AMD and DEA activate immune reaction when metabolically activated.

Mechanism of exacerbative effect of progesterone on drug-induced liver injury.

Drug-induced liver injury (DILI) is a major safety concern in drug development and clinical drug therapy. However, the underlying mechanism of DILI is little known. It is generally believed that women exhibit worse outcomes from DILI than men. Recently, we found that pretreatment of mice with estradiol attenuated halothane (HAL)-induced liver injury, whereas pretreatment with progesterone exacerbated it in female mice. To investigate the mechanism of sex difference of DILI, we focused on progesterone in this study. We found the exacerbating effect of progesterone in thioacetamide (TA), α-naphthylisothiocyanate, and dicloxacillin-induced liver injury only in female mice. Higher number of myeloperoxidase-positive mononuclear cells infiltrated into the liver and increased levels of Chemokine (C-X-C motif) ligand 1 and 2 (CXCL1 and CXCL2) and intercellular adhesion molecule-1 in the liver were observed. Interestingly, CXCL1 was slightly increased by progesterone pretreatment alone. Progesterone pretreatment increased the extracellular signal-regulated kinase (ERK) phosphorylation in HAL-induced liver injury. Pretreatment with U0126 (ERK inhibitor) significantly suppressed the exacerbating effect of progesterone and the expression of inflammatory mediators. In addition, pretreatment with gadolinium chloride (GdCl(3): inhibitor of Kupffer cells) significantly suppressed the exacerbating effect of progesterone pretreatment and the expression of inflammatory mediators. Moreover, posttreatment of RU486 (progesterone receptor antagonist) 1 h after the HAL or TA administration ameliorated the HAL- or TA-induced liver injury, respectively, in female mice. In conclusion, progesterone exacerbated the immune-mediated hepatotoxic responses in DILI via Kupffer cells and ERK pathway. The inhibition of progesterone receptor and decrease of the immune response may have important therapeutic implications in DILI.

Midterm results of surgical box line ablation for atrial fibrillation by bipolar radiofrequency.

OBJECTIVES: The surgical box lesion isolation of pulmonary veins and left atrium is recently reported to be superior to the conventional Cox maze IV procedure. The aim of this study is to investigate the midterm results of surgical box lesion ablation with the use of the bipolar radiofrequency energy performed at our institution. METHODS: From April 2004 to December 2008, 35 patients underwent the surgical box lesion ablation using bipolar radiofrequency and were followed for mean 31 months ranging from 3 to 58 months. RESULTS: There was no operative mortality. One patient (2.86%) needed electric cardioversion before discharge. One patient (2.86%) needed pacemaker implantation. At discharge, all patients were in normal sinus rhythm. During the follow-up period, the rate of sinus rhythm maintenance was 100%, the rate of freedom from antiarrhythmic medication was 42.9%, and the rate of freedom from thromboembolic episodes was 100%. CONCLUSIONS: The surgical box lesion ablation was a safe and effective procedure to terminate atrial fibrillation and restore sinus rhythm.

Progesterone receptor membrane component 1 modulates human cytochrome p450 activities in an isoform-dependent manner.

Cytochromes P450 (P450s) catalyze the metabolism of a wide spectrum of compounds. Recently, progesterone receptor membrane component 1 (PGRMC1), which shares a key structural motif with cytochrome b(5), has been reported to bind to sterol- or steroid-synthesizing P450s, enhancing their activities. In this study, we investigated whether PGRMC1 affects human drug-metabolizing P450 activities. Using coexpression systems for PGRMC1 and P450s (CYP3A4, CYP2C9, or CYP2E1) in HepG2 cells, we found that PGRMC1 decreased the V(max) values and increased the K(m) values of the CYP3A4 activities, and it decreased the V(max) values but did not affect the K(m) values of the CYP2C9 activities. In contrast, PGRMC1 hardly affected the CYP2E1 activities. These results suggest that PGRMC1 negatively modulates the drug-metabolizing activities of P450, although it was isoform but not substrate dependent. It is worth noting that coimmunoprecipitation analysis using coexpression systems for FLAG-PGRMC1 and Myc-P450s in human embryonic kidney 293 cells revealed that PGRMC1 interacts with all three P450s, although the affinity seemed to vary. In 29 human liver microsomes (HLMs), there was a 5-fold variability in the PGRMC1 protein levels. By the correlation analyses using the P450 activities and the PGRMC1 levels, we could neither observe the contribution of PGRMC1 to the P450 activities in HLMs nor that of the NADPH-cytochrome P450 reductase or cytochrome b(5). In conclusion, in contrast to sterol- or steroid-synthesizing P450s, we found that PGRMC1 negatively modulates the human drug-metabolizing activities of P450 through direct interaction. Further studies are needed to determine the clinical significance of PGRMC1 in the pharmacokinetics of drugs.

Estradiol and progesterone modulate halothane-induced liver injury in mice.

Drug-induced liver injury (DILI) is one of the major problems in drug development and clinical drug therapy. In general, it is believed that women exhibit worse outcomes from DILI than men. It is known that halothane (HAL), an inhaled anesthetic, rarely induces severe liver injury. The risk factors for severe HAL-induced liver injury (HILI) are female sex, genetics and adult age. To investigate the underlying mechanism by which women are more susceptible to HILI, we focused on two major female sex hormones, estradiol (E2) and progesterone (Prog). In this study, we first found that pretreatment of mice with E2 attenuated HILI, whereas pretreatment with Prog exacerbated HILI. E2 and Prog had no effects on the degree of metabolic activation, the ratio of GSH/GSSG or oxidative stress in the liver. We observed higher numbers of neutrophils infiltrated into the liver and increased hepatic mRNA levels of proinflammatory cytokines, tumor necrosis factor (TNF) α, interleukin (IL)-1ß and IL-6 and chemokines, CXCL1 and CXCL2 by pretreatment with Prog, whereas E2 pretreatment resulted in the opposite effects. These results suggest that E2 and Prog play a critical role in HILI via immune-related responses and female sex hormone balance might represent a risk factor for HILI.