Major Cardiovascular Events after Chemoradiotherapy with or without Durvalumab in Patients with Stage III Non-Small Cell Lung Cancer: Supplementary Analysis

PURPOSE/OBJECTIVE(S)

RTOG 0617 showed that cardiac events are relatively common after high-dose thoracic radiotherapy. The aim of this study was to investigate the incidence and risk of major cardiovascular events (MACE) after concurrent chemoradiotherapy (CCRT) with or without durvalumab in patients with stage III non-small cell lung cancer (NSCLC) using the data from a multi-institutional study in Japan.

MATERIALS/METHODS

Patients who received CCRT for stage III NSCLC between July 2018 and July 2019 were enrolled in a multi-institutional study in Japan. MACE was defined as follows: symptomatic pericardial effusion, acute coronary syndrome, pericarditis, significant arrhythmia, and heart failure. The cumulative incidence of MACE, accounting for death as a competing risk, was calculated. Pre-existing coronary heart disease (CHD) included coronary artery disease, congestive heart failure, peripheral vascular disease, stroke, and extensive coronary artery calcification. The association between patient/treatment-related factors and MACE was assessed by multivariate analysis.

RESULTS

Among 178 patients with a median follow-up period of 42.5 months, 13 patients developed MACEs. The 3-year cumulative incidence of MACE was 6.9% (95% confidence interval [CI], 4.0-11.9%). Univariate analysis showed that female sex and mean heart dose (MHD) were marginally associated (3-year cumulative incidence, male 5.6% vs. female 12.1%; P = 0.12; MHD ≥ 6.3 Gy 4.8% vs. < 6.3 Gy 9.1%; P = 0.13), and pre-existing CHD was significantly associated with an increased risk of MACE (no CHD 4.3% vs. CHD 16.8%; P = 0.026). Consolidation durvalumab was not associated with an increased risk of MACE (no durvalumab 5.2% vs. durvalumab 7.4%; P = 0.89). Multivariate analysis showed that pre-existing CHD was significantly associated with MACE (hazard ratio, 4.22; 95% CI, 1.30-13.7; P = 0.016).

CONCLUSION

The incidence of MACE based on the real-world data in Japan was lower than previously reported. Pre-existing CHD was associated with an increased risk of MACE after CCRT in patients with stage III NSCLC, whereas the administration of consolidation durvalumab was not associated with an increased risk of MACE.

Real-World Study of Overall Survival in Patients with Stage III Non-Small Cell Lung Cancer Treated with Chemoradiotherapy with or without Durvalumab and an Exploratory Analysis of Effective Radiation Dose to the Immune Cells

PURPOSE/OBJECTIVE(S)

To investigate the real-world data on overall survival (OS) in patients with stage III non-small cell lung cancer (NSCLC) treated with concurrent chemoradiotherapy (CCRT) with or without consolidation durvalumab, and to perform an exploratory analysis on effective radiation dose to the immune cells (EDIC).

MATERIALS/METHODS

In our multi-institutional retrospective study, patients who received CCRT between July 2018 and July 2019 for stage III NSCLC in Japan were investigated. EDIC was estimated using mean lung dose, mean heart dose, body volume, body mean dose, and body weight, as reported in the secondary analysis of RTOG 0617. The cut-off value of EDIC was calculated using the maximally selected log-rank statistics.

RESULTS

One hundred and seventy-eight patients were eligible for the analysis (136 patients, CCRT with consolidation durvalumab [CCRT+D] cohort; 42 patients, CCRT cohort). The median follow-up period was 42.5 months. Three-year OS rates were 59.8% in the overall cohort: 60.5% in the CCRT+D cohort, and 58.0% in the CCRT cohort with no significant difference (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.45-1.27; P = 0.29). Univariate analysis showed that ECOG-PS, smoking history, histology, EGFR mutational status, gross tumor volume and EDIC were significantly associated with OS. Multivariate analysis showed that ECOG-PS 2, gross tumor volume ≥ 57 cm3 and EDIC ≥ 4.4 Gy were associated with poor OS. Among 21 EGFR-mutated patients, 3 year-OS rates were 64.7% in the CCRT+D cohort and 100% in the CCRT cohort, while 3 year-OS rates were 68.8% and 58.7% among 90 EGFR wild-type patients. Three-year OS rates were 64.6% and 47.6% for EDIC < 4.4 Gy and EDIC ≥ 4.4 Gy in the overall cohort (HR, 1.82; 95% CI, 1.14-2.90; P = 0.015). In the subgroup analysis, 66.3% vs. 44.4% in the CCRT+D cohort (HR, 2.01; 95% CI, 1.17-3.47; P = 0.016), and 59.0% vs. 56.1% in the CCRT cohort (HR, 1.20; 95% CI, 0.48-3.01; P = 0.70), respectively.

CONCLUSION

Our real-world data in Japan showed that there was no significant difference in OS between the CCRT+D cohort and the CCRT cohort. High EDIC could be a risk for poor OS in patients treated with CCRT and consolidation durvalumab compared with those treated with CCRT.

Computational Study on the Thermal Conductivity of a Protein

Protein molecules are thermally fluctuating and tightly packed amino acid residues strongly interact with each other. Such interactions are characterized in terms of heat current at the atomic level. We calculated the thermal conductivity of a small globular protein, villin headpiece subdomain, based on the linear response theory using equilibrium molecular dynamics simulation. The value of its thermal conductivity was 0.3 ± 0.01 [W m^-1 K^-1], which is in good agreement with experimental and computational studies on the other proteins in the literature. Heat current along the main chain was dominated by local vibrations in the polypeptide bonds, with amide I, II, III, and A bands on the Fourier transform of the heat current autocorrelation function.

Chrysanthemum morifolium Extract Ameliorates Doxorubicin-Induced Cardiotoxicity by Decreasing Apoptosis

It is well known that the anthracycline anticancer drug doxorubicin (DOX) induces cardiotoxicity. Recently, Chrysanthemum morifolium extract (CME), an extract of the purple chrysanthemum flower, has been reported to possess various physiological activities such as antioxidant and anti-inflammatory effects. However, its effect on DOX-induced cardiotoxicity is still unknown. An 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT)assay revealed that 1 mg/mL of CME reduced DOX-induced cytotoxicity in H9C2 cells but not in MDA-MB-231 cells. A TUNEL assay indicated that CME treatment improved DOX-induced apoptosis in H9C2 cells. Moreover, DOX-induced increases in the expression levels of p53, phosphorylated p53, and cleaved caspase-3,9 were significantly suppressed by CME treatment. Next, we investigated the effect of CME in vivo. The results showed that CME treatment substantially reversed the DOX-induced decrease in survival rate. Echocardiography indicated that CME treatment also reduced DOX-induced left ventricular systolic dysfunction, and a TUNEL assay showed that CME treatment also suppressed apoptosis in the mouse heart. These results reveal that CME treatment ameliorated DOX-induced cardiotoxicity by suppressing apoptosis. Further study is needed to clarify the effect of CME on DOX-induced heart failure in humans.

Ecklonia stolonifera Okamura Extract Suppresses Myocardial Infarction-Induced Left Ventricular Systolic Dysfunction by Inhibiting p300-HAT Activity

Ecklonia stolonifera Okamura extract (ESE) has been reported to have various bioactive effects, but its effects on cardiovascular disease have not yet been investigated. First, primary neonatal rat cultured cardiomyocytes were treated with ESE and stimulated with phenylephrine (PE) for 48 h. ESE (1000 µg/mL) significantly suppressed PE-induced cardiomyocyte hypertrophy, hypertrophy-related gene transcription, and the acetylation of histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity. Next, one week after myocardial infarction (MI) surgery, rats (left ventricular fractional shortening (LVFS) < 40%) were randomly assigned to three groups: vehicle (saline, n = 9), ESE (0.3 g/kg, n = 10), or ESE (1 g/kg, n = 10). Daily oral administration was carried out for 8 weeks. After treatment, LVFS was significantly higher in the ESE (1 g/kg) group than in the vehicle group. The ESE treatments also significantly suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, hypertrophy- and fibrosis-related gene transcription, and the acetylation of histone H3K9. These results suggest that ESE suppressed both hypertrophic responses in cardiomyocytes and the development of heart failure in rats by inhibiting p300-HAT activity. Thus, this dietary extract is a potential novel therapeutic strategy for heart failure in humans.

The Selective Serotonin 2A Receptor Antagonist Sarpogrelate Prevents Cardiac Hypertrophy and Systolic Dysfunction via Inhibition of the ERK1/2-GATA4 Signaling Pathway

Drug repositioning has recently emerged as a strategy for developing new treatments at low cost. In this study, we used a library of approved drugs to screen for compounds that suppress cardiomyocyte hypertrophy. We identified the antiplatelet drug sarpogrelate, a selective serotonin-2A (5-HT_2A) receptor antagonist, and investigated the drug's anti-hypertrophic effect in cultured cardiomyocytes and its effect on heart failure in vivo. Primary cultured cardiomyocytes pretreated with sarpogrelate were stimulated with angiotensin II, endothelin-1, or phenylephrine. Immunofluorescence staining showed that sarpogrelate suppressed the cardiomyocyte hypertrophy induced by each of the stimuli. Western blotting analysis revealed that 5-HT_2A receptor level was not changed by phenylephrine, and that sarpogrelate suppressed phenylephrine-induced phosphorylation of ERK1/2 and GATA4. C57BL/6J male mice were subjected to transverse aortic constriction (TAC) surgery followed by daily oral administration of sarpogrelate for 8 weeks. Echocardiography showed that 5 mg/kg of sarpogrelate suppressed TAC-induced cardiac hypertrophy and systolic dysfunction. Western blotting revealed that sarpogrelate suppressed TAC-induced phosphorylation of ERK1/2 and GATA4. These results indicate that sarpogrelate suppresses the development of heart failure and that it does so at least in part by inhibiting the ERK1/2-GATA4 signaling pathway.

Abstract P381: Ecklonia Stolonifera Okamura Extract Suppresses Hypertrophic Responses In Cardiomyocytes And Development Of Heart Failure By Inhibiting P300-HAT Activity

Introduction: Heart failure is the leading cause of death in the world. Cardiomyocyte hypertrophy is observed during the development of heart failure, suggesting that its inhibition is a potential target for the prevention and treatment of heart failure. In this study, we screened a natural compound library using cultured cardiomyocytes and found that Ecklonia stolonifera Okamura extract (ESE) suppressed cardiomyocyte hypertrophy. ESE, a perennial brown alga, has been reported to have various bioactive effects, such as antioxidant and anti-inflammatory activity, but its effect on heart failure is still unclear. Therefore, we investigated whether ESE has an inhibitory effect on cardiomyocyte hypertrophic response and on the progression of heart failure in post-myocardial infarction (MI) rats.

Methods and Results: First, primary cultured cardiomyocytes from neonatal rats were treated with ESE and then stimulated with phenylephrine (PE) for 48 hours. ESE (1000 μg/mL) significantly suppressed PE-induced increases in cardiomyocyte surface area, hypertrophic response gene transcription, and acetylation of histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity (IC50: 505 μg/mL). Next, one week after the ligation of the left anterior descending artery, rats with moderate MI (left ventricular fractioning shorting (LVFS) <40%) were randomly assigned to three groups: vehicle (saline) (n=9), ESE (0.3 g/kg) (n=10), or ESE (1 g/kg) (n=10). Daily oral administration was repeated for 8 weeks. After treatment, LVFS was significantly higher in the ESE (1 g/kg) group (23.3 ± 0.7%, p<0.05) than in the vehicle group (16.6 ± 1.3%). Next, the hearts were isolated and histological analysis, evaluation of gene transcription, and measurement of histone H3K9 acetylation. were performed. ESE treatment significantly suppressed MI-induced increases both in myocardial cell diameter and in the mRNA levels of hypertrophic response genes. ESE also inhibited MI-induced perivascular fibrosis and the acetylation of histone H3K9.

Conclusion: These results suggest that ESE suppresses both hypertrophic responses in cardiomyocytes and the development of heart failure by inhibiting p300-HAT activity. Further studies are needed to clarify the effectiveness of ESE for heart failure therapy.

Discovery of DS79932728: A Potent, Orally Available G9a/GLP Inhibitor for Treating β-Thalassemia and Sickle Cell Disease

Therapeutic reactivation of the γ-globin genes for fetal hemoglobin (HbF) production is an attractive strategy for treating β-thalassemia and sickle cell disease. It was reported that genetic knockdown of the histone lysine methyltransferase EHMT2/1 (G9a/GLP) is sufficient to induce HbF production. The aim of the present work was to acquire a G9a/GLP inhibitor that induces HbF production sufficiently. It was revealed that tetrahydroazepine has versatility as a side chain in various skeletons. We ultimately obtained a promising aminoindole derivative (DS79932728), a potent and orally bioavailable G9a/GLP inhibitor that was found to induce γ-globin production in a phlebotomized cynomolgus monkey model. This work could facilitate the development of effective new approaches for treating β-thalassemia and sickle cell disease.

Discovery of novel histone lysine methyltransferase G9a/GLP (EHMT2/1) inhibitors: Design, synthesis, and structure-activity relationships of 2,4-diamino-6-methylpyrimidines

The discovery and optimization of a novel series of G9a/GLP (EHMT2/1) inhibitors are described. Starting from known G9a/GLP inhibitor 5, efforts to explore the structure-activity relationship and optimize drug properties led to a novel compound 13, the side chain of which was converted to tetrahydroazepine. Compound 13 showed increased G9a/GLP inhibitory activity compared with compound 5. In addition, compound 13 exhibited improved human ether-a-go-go related gene (hERG) inhibitory activity over compound 5 and also improved pharmacokinetic profile in mice (oral bioavailability: 17 to 40%). Finally, the co-crystal structure of G9a in complex with compound 13 provides the basis for the further development of tetrahydroazepine-based G9a/GLP inhibitors.

Outbreaks of ulcerative disease associated with ranavirus infection in barcoo grunter, Scortum barcoo (McCulloch & Waite)

In 2013, an outbreak of ulcerative disease associated with ranavirus infection occurred in barcoo grunter, Scortum barcoo (McCulloch & Waite), farms in Thailand. Affected fish exhibited extensive haemorrhage and ulceration on skin and muscle. Microscopically, the widespread haemorrhagic ulceration and necrosis were noted in gill, spleen and kidney with the presence of intracytoplasmic eosinophilic inclusion bodies. When healthy barcoo grunter were experimentally challenged via intraperitoneal and oral modes with homogenized tissue of naturally infected fish, gross and microscopic lesions occurred with a cumulative mortality of 70-90%. Both naturally and experimentally infected fish yielded positive results to the ranavirus-specific PCR. The full-length nucleotide sequences of major capsid protein gene of ranaviral isolates were similar to largemouth bass virus (LMBV) and identical to largemouth bass ulcerative syndrome virus (LBUSV), previously reported in farmed largemouth bass (Micropterus salmoides L.), which also produced lethal ulcerative skin lesions. To the best of our knowledge, this is the first report of a LMBV-like infection associated with skin lesions in barcoo grunter, adding to the known examples of ranavirus infection associated with skin ulceration in fish.

Anthelmintic activity of Rosmarinus officinalis against Dactylogyrus minutus (Monogenea) infections in Cyprinus carpio

Monogenean parasites are important ectoparasites of fish, and are responsible for severe economic impacts in the aquaculture industry. They are usually treated with chemicals, but the chemicals can have harmful side effects in the fish and may pose threats to human health. Rosemary (Rosmarinus officinalis) is a common medicinal herb, with antimicrobial and antitumor properties. Here, we examined the anthelmintic activity of rosemary extract against the monogenean (Dactylogyrus minutus) in vitro and in vivo using bath treatment and oral administration. The in vitro experiments showed that parasite survival was affected by both rosemary extract concentration and the solvent (water and ethanol). Parasites were dead at 61.8±5.6 and 7.8±1.4min when exposed to 100 and 200g aqueous rosemary extract solution/L of water respectively. It took 166.7±48.2 and 5.4±1.01min to kill the parasites when exposed to 1 and 32g ethanol rosemary extract solution/L of water respectively. Moreover, pure component of rosemary extract obtained commercially used in in vitro experiments showed that 1,8-Cineole was the most toxic component of the main components tested. Parasite intensity and prevalence in fish exposed to 50 and 100g aqueous rosemary solution/L water for 30min were significantly lower than they were in controls (p<0.05). In oral treatment experiments, diets of Cyprinus carpio were supplemented with eight different concentrations of aqueous rosemary extract. The intensity of parasites was significantly less in fish fed for 30days with feed containing 60, 80 and 100ml aqueous extract/100g feed than in control (p<0.05). Together these results indicate that rosemary is a promising candidate for prevention and control of monogenean infection.

Smad9 is a new type of transcriptional regulator in bone morphogenetic protein signaling

Smad1, Smad5 and Smad9 (also known as Smad8) are activated by phosphorylation by bone morphogenetic protein (BMP)-bound type I receptor kinases. We examined the role of Smad1, Smad5, and Smad9 by creating constitutively active forms (Smad(DVD)). Transcriptional activity of Smad9(DVD) was lower than that of Smad1(DVD) or Smad5(DVD), even though all three Smad(DVD)s associated with Smad4 and bound to the target DNA. The linker region of Smad9 was sufficient to reduce transcriptional activity. Smad9 expression was increased by the activation of BMP signaling, similar to that of inhibitory Smads (I-Smads), and Smad9 reduced BMP activity. In contrast to I-Smads, however, Smad9 did not inhibit the type I receptor kinase and suppressed the constitutively active Smad1(DVD). Smad9 formed complexes with Smad1 and bound to DNA but suppressed the transcription of the target gene. Taken together, our findings suggest that Smad9 is a new type of transcriptional regulator in BMP signaling.

ACVR1 (587T>C) mutation in a variant form of fibrodysplasia ossificans progressiva: second report

Fibrodysplasia ossificans progressiva (FOP) is a rare, congenital disorder caused by heterozygous mutation of the bone morphogenetic protein type I receptor ACVR1. Various forms of atypical FOP have recently been identified, and a novel mutation, ACVR1 (587T>C), was reported in 2011. We report on the second patient worldwide with ACVR1 (587T>C) mutation. A 22-year-old Japanese male with no family history of heterotopic ossification did not show any malformation of the great toes and showed normal development from birth to the age of 17 years, when heterotopic ossification appeared in the lumbar area. The clinical symptoms were similar to those reported previously: the delayed onset with a slower and mild clinical course and little finger camptodactyly. Gene analysis revealed that the patient was heterozygous for ACVR1 (587T>C) mutation, the same one as reported in 2011, suggesting a correlation between the location of the mutation and the clinical symptoms. This second report of ACVR1 (587T>C) mutation worldwide is particularly meaningful in that it highlights the difference between clinical symptoms of the first reported patient with ACVR1 (587T>C) mutation and those of classic FOP.

Disease-causing allele-specific silencing against the ALK2 mutants, R206H and G356D, in fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP) is an autosomal dominant congenital disorder characterized by progressive heterotopic bone formation. Currently, no definitive treatment exists for FOP. The activin receptor type IA / activin-like kinase 2 (ACVR1/ALK2) gene has been identified as the responsible gene for FOP, and disease-associated ALK2 mutations have been found. Chemical inhibitors to the pathogenic ALK2 receptors are considered possible medical agents for FOP, but their adverse effects on normal ALK2 and other receptors cannot be excluded. Here we describe another treatment strategy for FOP using allele-specific RNA interference (ASP-RNAi), and show modified small interfering RNAs (siRNAs) conferring allele-specific silencing against disease-causing ALK2 mutants found in FOP, without affecting normal ALK2 allele. Thus, the siRNAs presented here may become novel therapeutic agents for FOP, and their induced ASP-RNAi may pave the way for the achievement of radical treatment of FOP and/or for the relief of its severe symptoms.

Molecular diagnosis of Myxobolus spirosulcatus associated with encephalomyelitis of cultured yellowtail, Seriola quinqueradiata Temminck & Schlegel

Mass mortality of cultured yellowtail, Seriola quinqueradiata, has recently been reported from fish farms in western Japan. Previous studies revealed that diseased fish were characterized by encephalomyelitis and presporogonic stages of a myxosporean-like parasite in the spinal cord. However, the parasite has remained unidentified because of the lack of mature stages being present. Thus, in the present study, analysis of the small subunit ribosomal DNA (18S rDNA) of the parasite as well as in situ hybridization (ISH) studies using histological sections of the infected tissue was conducted. The 18S rDNA of the myxosporean had higher sequence similarities with those of bile-duct-infecting myxosporeans rather than those infecting nervous tissues and was identified as Myxobolus spirosulcatus. The ISH using specific probes demonstrated that the DNA amplified was derived from the multinuclear organisms found in histological sections. A highly sensitive and specific PCR-based assay for M. spirosulcatus was developed, which revealed a high prevalence of infection in cultured yellowtail that exhibited the clinical signs of encephalomyelitis.

BMP signalling permits population expansion by preventing premature myogenic differentiation in muscle satellite cells

Satellite cells are the resident stem cells of adult skeletal muscle, supplying myonuclei for homoeostasis, hypertrophy and repair. In this study, we have examined the role of bone morphogenetic protein (BMP) signalling in regulating satellite cell function. Activated satellite cells expressed BMP receptor type 1A (BMPR-1A/Alk-3) and contained phosphorylated Smad proteins, indicating that BMP signalling is operating during proliferation. Indeed, exogenous BMP4 stimulated satellite cell division and inhibited myogenic differentiation. Conversely, interfering with the interactions between BMPs and their receptors by the addition of either the BMP antagonist Noggin or soluble BMPR-1A fragments, induced precocious differentiation. Similarly, blockade of BMP signalling by siRNA-mediated knockdown of BMPR-1A, disruption of the intracellular pathway by either Smad5 or Smad4 knockdown or inhibition of Smad1/5/8 phosphorylation with Dorsomorphin, also caused premature myogenic differentiation. BMP signalling acted to inhibit the upregulation of genes associated with differentiation, in part, through regulating Id1. As satellite cells differentiated, Noggin levels increased to antagonise BMP signalling, since Noggin knockdown enhanced proliferation and impeded myoblast fusion into large multinucleated myotubes. Finally, interference of normal BMP signalling after muscle damage in vivo perturbed the regenerative process, and resulted in smaller regenerated myofibres. In conclusion, BMP signalling operates during routine satellite cell function to help coordinate the balance between proliferation and differentiation, before Noggin is activated to antagonise BMPs and facilitate terminal differentiation.

Mild resistance to thyroid hormone with a truncated thyroid hormone receptor beta

Recent studies have revealed mutations in the thyroid hormone receptor beta (TR beta) gene as a cause of the most cases of the thyroid hormone resistance syndrome. We have identified a novel nonsense mutation in codon 449 in the 3' end of exon 10 in the TR beta gene in a 16-year-old male patient with generalized resistance to thyroid hormone who also had familial thyroxine binding globulin deficiency. Receptor protein generated from this gene is thought to be 13 amino acid deficient at carboxy-terminus. Resistance to thyroid hormone was mild at least when the patient was evaluated. The patient was eumetabolic in the presence of elevated plasma-free thyroid hormone levels, and both thyrotrope and peripheral tissues responded to triiodothyronine (T3) administration. This mildness of resistance is in contrast to severe resistance to thyroid hormone in two previously reported cases with truncated receptors in which 16 amino acids or 11 amino acids were deficient at C-terminus. Thus, truncation of C-terminus of thyroid hormone receptor beta does not uniformly produce sever resistance.

Uncommon electrocardiographic changes corresponding to symptoms during recurrent pulmonary embolism as documented by computed tomography scans

Electrocardiographic (ECG) findings of pulmonary embolism (PE) include S1Q3T3 pattern, right bundle-branch block, right-axis deviation, and T-wave inversion in medial precordial leads. We report other uncommon ECG changes associated with various symptoms during recurrent PE as documented by computed tomography (CT) scans in a single patients. An 83-year-old woman was admitted with PE secondary to deep venous thrombosis in the left leg. During episodes of chest pain, ECG showed QTc prolongation (480 ms) with new T-wave inversion in leads III, aVF, and V1-V3, and ST-segment depression in leads V5-V6. Despite adequate anticoagulant therapy, recurrent episodes of PE occurred in the hospital. When the patient experienced sudden chest tightness, ECG showed a new S-wave notch in lead V1 and clock-wise rotation with sinus tachycardia. She also experienced transient syncope with hypotension. At this time, ECG showed transient atrioventricular junctional rhythm followed by sinus arrest, and CT scan showed a new massive embolus in the main pulmonary trunk with right ventricular dilatation, as demonstrated by echocardiography. The mechanism responsible for QTc prolongation with ST-T changes, the S-wave notch in lead V1 with clockwise rotation, or atrioventricular junctional rhythm with sinus arrest during PE may be associated with myocardial ischemia, acute right ventricular overload, or vagal reflex, respectively.

Exercise-induced QTc-interval changes for predicting improvement in regional blood flow in ischemic myocardium and cardiac output after coronary angioplasty in patients with right bundle-branch block

BACKGROUND

We have previously shown that QT-interval changes are more useful than ST-T changes in evaluating the severity of exercise-induced myocardial ischemia in patients with right bundle-branch block (RBBB).

HYPOTHESIS

The purpose of this study was to evaluate whether the improvement in regional myocardial blood flow (RMBF) in ischemic areas and cardiac output after percutaneous transluminal coronary angioplasty (PTCA) can be predicted by exercise-induced QT-interval changes prior to PTCA.

METHODS

The RMBF and cardiac output were quantified with nitrogen-13 ammonia positron emission tomography at rest and during exercise in 20 patients with RBBB and ischemic heart disease before and 6 months after PTCA, and in 9 healthy volunteers.

RESULTS

Before PTCA, exercise-induced prolongation by < 20 ms or shortening of the Bazett-corrected QT (QTc) interval (454 +/- 38 to 451 +/- 41 ms, p = NS) was observed in 13 patients (Group 1) and prolongation by > or = 20 ms (429 +/- 44 to 466 +/- 50 ms, p < 0.002) was observed in 7 (Group 2). The number of regions of exercise-induced ischemia was significantly greater in Group 2 than in Group 1 (4.0 +/- 1.2 vs. 2.1 +/- 1.2, p < 0.01). The RMBF in regions of exercise-induced ischemia and cardiac output at rest was not significantly different between Groups 1 and 2, whereas during exercise both the parameters were significantly lower in Group 2 than in Group 1 (both p < 0.05). After successful PTCA, RMBF both at rest and during exercise improved significantly in Group 1 (0.67 +/- 0.04 to 0.71 +/- 0.06 ml/min/g, 0.74 +/- 0.05 to 0.84 +/- 0.08 ml/min/g; both p < 0.0001), but did not improve significantly in Group 2 (0.63 +/- 0.05 to 0.65 +/- 0.07 ml/min/g, 0.65 +/- 0.04 to 0.69 +/- 0.11 ml/ min/g; both p = NS). Cardiac output during exercise improved significantly in Group 1 (6.4 +/- 0.7 to 7.4 +/- 0.9 l/min; p < 0.002) but not in Group 2 (5.7 +/- 0.6 to 5.9 +/- 0.6 l/min; p = NS).

CONCLUSIONS

Our results suggest that the marked prolongation of the QTc interval induced by pre-PTCA exercise may predict a lack of improvement in RMBF in ischemic areas and cardiac output after PTCA in patients with RBBB and ischemic heart disease.

Application of devices for safe laparoscopic hepatectomy

The continuing evolution of a variety of laparoscopic instrument and device has been gradually applied to the laparoscopic hepatectomy in many countries. Recent experience has persuaded us that there are great potential benefits derived from laparoscopic hepatectomy and much has been learned about patient selection, the grade of surgical difficulty with respect to tumor location, and the required instrumentation. Among these efforts, various ways of hepatic parenchymal transection with mechanical devices have been attempted and continuing to innovate to perform safe laparoscopic hepatectomy Important technologic developments and improved endoscopic procedures are being established equipment modifications. For safe laparoscopic hepatectomy, it is important to have all necessary equipment. The intraoperative laparoscopic ultrasonography, microwave coagulators, ultrasonic dissection, argon beam coagulators, laparoscopic coagulation shears, endolinear staplers and TissueLink monopolar sealer are essential. This procedure is in need that well experienced endoscopic surgeon and well-experienced liver surgeon should be collaborated in laparoscopic hepatectomy and the indications are strictly followed based upon the location and size of tumors. Finally critical determinant for success and safe laparoscopic hepatectomy is through familiarity with the relevant laparoscopic instruments and equipments. Laparoscopic hepatectomy is expected to develop further in the future as a new surgical instrument, equipment and method, which improves patients' quality of life.

Involvement of elevated expression of multiple cell-cycle regulator, DTL/RAMP (denticleless/RA-regulated nuclear matrix associated protein), in the growth of breast cancer cells

To investigate the detailed molecular mechanism of mammary carcinogenesis and discover novel therapeutic targets, we previously analysed gene expression profiles of breast cancers. We here report characterization of a significant role of DTL/RAMP (denticleless/RA-regulated nuclear matrix associated protein) in mammary carcinogenesis. Semiquantitative RT-PCR and northern blot analyses confirmed upregulation of DTL/RAMP in the majority of breast cancer cases and all of breast cancer cell lines examined. Immunocytochemical and western blot analyses using anti-DTL/RAMP polyclonal antibody revealed cell-cycle-dependent localization of endogenous DTL/RAMP protein in breast cancer cells; nuclear localization was observed in cells at interphase and the protein was concentrated at the contractile ring in cytokinesis process. The expression level of DTL/RAMP protein became highest at G(1)/S phases, whereas its phosphorylation level was enhanced during mitotic phase. Treatment of breast cancer cells, T47D and HBC4, with small-interfering RNAs against DTL/RAMP effectively suppressed its expression and caused accumulation of G(2)/M cells, resulting in growth inhibition of cancer cells. We further demonstrate the in vitro phosphorylation of DTL/RAMP through an interaction with the mitotic kinase, Aurora kinase-B (AURKB). Interestingly, depletion of AURKB expression with siRNA in breast cancer cells reduced the phosphorylation of DTL/RAMP and decreased the stability of DTL/RAMP protein. These findings imply important roles of DTL/RAMP in growth of breast cancer cells and suggest that DTL/RAMP might be a promising molecular target for treatment of breast cancer.

Bone regeneration by synthetic octacalcium phosphate and its role in biological mineralization

Octacalcium phosphate (Ca8H2(PO4)6 * 5H2O; OCP) has been advocated to be a precursor of biological apatite crystals in bone and tooth. Recent studies, using physical techniques, showed that OCP is present as a transient phase during biological apatite formation in human dentin, porcine enamel and murine bone. However, there is still a controversy regarding the chemical nature of the first mineral formed in the biominerals. A number of studies have demonstrated that synthetic OCP shows bone regenerative and biodegradable characteristics, rather than other calcium phosphate bone substitute materials, such as hydroxyapatite (Ca10(PO4)6(OH)2; HA) ceramic. It seems likely that synthetic OCP may be an alternative to autogenous bone graft. It is known that OCP contains alternative layers of water molecules and an apatite structure, and that the transition of OCP to HA is likely to be spontaneous and irreversible. The conversion process induces modification of local environment adjacent to OCP surface, including the changes in adsorption of serum proteins and concentration of calcium and inorganic phosphate ions. This article reviews the possible application to bone regeneration by synthetic OCP and the mechanism to enhance bone regeneration in relation to biological mineralization in bone and tooth.

Elevation of matrix metalloproteinases and interleukin-6 in the culprit coronary artery of myocardial infarction

BACKGROUND

Interleukin-6 (IL-6) and metalloproteinases (MMPs) are involved in the instability of vulnerable plaque associated with the induction of acute myocardial infarction (AMI). We examined the regional changes of cytokines, MMPs and adhesion molecules in patients with AMI to elucidate how these factors are involved in the onset of AMI.

MATERIALS AND METHODS

One hundred and twenty-two patients with AMI were included. Blood was aspirated from the culprit coronary artery with a thrombectomy catheter, and was also sampled from peripheral veins during the coronary intervention. Control samples were obtained from the peripheral blood of age-matched patients.

RESULTS

The serum levels of IL-6 (P < 0.05), tumour necrosis factor-alpha (P < 0.005), MMP-1 (P < 0.001), MMP-13 (P < 0.001), soluble intercellular adhesion molecule-1 (P < 0.005), and soluble vascular cellular adhesion molecule-1 (P < 0.05) in peripheral blood were significantly higher in the AMI group than in the controls. Aspirated serum contained significantly higher levels of IL-6 (P < 0.001), MMP-1 (P < 0.001), and MMP-13 (P < 0.05) compared to the peripheral blood of AMI. Serum IL-6 levels were significantly higher in the aspirated than in the peripheral blood in the patients hospitalized within 6 h and 6-12 h, but were similar in the aspirated and peripheral blood of the patients hospitalized 12-24 h after the onset of AMI. There were no differences between the aspirated serum and peripheral blood in the levels of interleukin-1beta and MMP-2.

CONCLUSIONS

The levels of MMP-1, MMP-13 and IL-6 were higher in the culprit coronary artery than in the peripheral blood. These factors appear to be involved in the early stage of AMI.

CDC20, a potential cancer therapeutic target, is negatively regulated by p53

The p53 protein inhibits malignant transformation through direct and indirect regulation of transcription of many genes related to cell cycle, apoptosis and cellular senescence. A number of genes induced by p53 have been well characterized, but biological significance of genes whose expression was suppressed by p53 is still largely undisclosed. To clarify the roles of p53-suppressive genes in carcinogenesis, we analysed two data sets of whole-genome expression profiles, one for cells in which wild-type p53 was exogenously introduced and the other for a large number of clinical cancer tissues. Here, we identified CDC20 that was frequently upregulated in many types of malignancies and remarkably suppressed by ectopic introduction of p53. CDC20 expression was suppressed by genotoxic stresses in p53- and p21-dependent manners through CDE-CHR elements in the CDC20 promoter. Furthermore, small interference RNA (siRNA)-mediated silencing of p53 induced CDC20 expression in normal human dermal fibroblast cells. As we expected, treatment of cancer cells with siRNA against CDC20 induced G(2)/M arrest and suppressed cell growth. Our results indicate that p53 inhibits tumor cell growth through the indirect regulation of CDC20 and that CDC20 might be a good potential therapeutic target for a broad spectrum of human cancer.

Binding of Bacillus thuringiensis Cry1A toxins to brush border membrane vesicles of midgut from Cry1Ac susceptible and resistant Plutella xylostella

Plutella xylostella strain resistant (PXR) to Bacillus thuringiensis Cry1Ac toxin was not killed at even more than 1000 microg Cry1Ac/g diet but killed by Cry1Ab at 0.5 microg/g diet. In contrast, susceptible strain (PXS) was killed by Cry1Ac at 1 microg/g diet. Cy3-labeld Cry1A(s) binding to brush border membrane vesicles (BBMV) prepared from both strains were analyzed with direct binding assay. The Kd value of Cry1Aa to both BBMV was almost identical: 213.2 and 205.8 nM, and 263.5 and 265.0 nM for Cry1Ac. The highest Kd values were in Cry1Ab which showed most effective insecticidal activity in PXS and PXR, 2126 and 2463 nM, respectively. These results clearly showed that the BBMV from PXR and PXS could equally bind to Cry1Ac. The binding between BBMV and Cy3-labeled Cry1Ac was inhibited only by anti-175 kDa cadherin-like protein (CadLP) and -252 kDa protein antisera, but not by anti-120 kDa aminopeptidase. This supports that resistance in PXR resulted from the abortion of pore formation after the binding of Cry1Ac to the BBMV. And furthermore, the importance of 175K CadLP and P252 proteins in those bindings was suggested. We briefly discuss possible mechanisms of the resistance.

Molecular typing by pulsed-field gel electrophoresis of Flavobacterium psychrophilum isolates derived from Japanese fish

Sixty-four isolates of Flavobacterium psychrophilum from ayu, Plecoglossus altivelis altivelis (Temminck & Schlegel), and other fish (n=16) in Japan and the type strain (NCIMB 1947(T)) were typed using pulsed-field gel electrophoresis (PFGE) with endonuclease BlnI and XhoI. These isolates were classified into 20 clusters and 42 genotypes by PFGE analysis. The most predominant cluster of isolates from ayu was cluster XII (n=20), followed by clusters XVII, XVI, XX, XI, IX, X, XIII and XV; the remaining 17 isolates from other fish were divided into clusters I, II, III, IV, V, VI, VII, VIII, XIV, XVIII and XIX. The PFGE genotype of isolates from ayu clearly differed from those of other fish. The isolates from ayu in Gunma Prefecture belonged to clusters XII, XVI, XVII and XX, and the strains of three of these clusters (XII, XVII and XX) were isolated from ayu in 15 of 19 prefectures. PFGE typing enabled more accurate classification of isolates into clusters than previously achieved by analysing the restriction fragment length polymorphism of PCR products. These results suggest that F. psychrophilum isolated from ayu and other fish are genetically different and strains with several PFGE types have spread within Japan.

Involvement of upregulation of DEPDC1 (DEP domain containing 1) in bladder carcinogenesis

In an attempt to disclose mechanisms of bladder carcinogenesis and discover novel target molecules for development of treatment, we applied a cDNA microarray to screen genes that were significantly transactivated in bladder cancer cells. Among the upregulated genes, we here focused on a novel gene, (DEPDC1) DEP domain containing 1, whose overexpression was confirmed by northern blot and immunohistochemical analyses. Immunocytochemical staining analysis detected strong staining of endogenous DEPDC1 protein in the nucleus of bladder cancer cells. Since DEPDC1 expression was hardly detectable in any of 24 normal human tissues we examined except the testis, we considered this gene-product to be a novel cancer/testis antigen. Suppression of DEPDC1 expression with small-interfering RNA significantly inhibited growth of bladder cancer cells. Taken together, these findings suggest that DEPDC1 might play an essential role in the growth of bladder cancer cells, and would be a promising molecular-target for novel therapeutic drugs or cancer peptide-vaccine to bladder cancers.

Bacterial translocation in small intestinal ischemia-reperfusion injury and efficacy of Anti-CINC antibody treatment

The involvement of bacterial translocation in small intestinal ischemia-reperfusion injuries and the efficacy of using anti-CINC antibodies for treatment were investigated. A model for ischemia-reperfusion injury of the small intestine was constructed by clamping the supramesenteric artery (for 90 min) in rats. Anti-CINC antibodies and saline were given just before the induction of ischemia in the treatment group and the control group, respectively. Six hours after reperfusion, bacteria were detected in the mesenteric lymph nodes, but the 'bacteria-positive' rate was significantly lower in the treatment group than in the control group. Bacterial cultures and endotoxins in the blood were negative in both groups up to 24 h later. The plasma cytokine levels showed similar variations, although the increases were significantly lower after reperfusion in the treatment group. In addition, the degrees of neutrophil infiltration and mucosal injury were attenuated in the small intestine, and the structure of the liver was maintained. Furthermore, the 1-week survival was improved. These results suggest that bacterial translocation occurred predominantly via the lymphatic system and that anti-CINC antibody treatment exerted a protective effect against small intestinal ischemia-reperfusion injury.