Percutaneous shunt vessel embolisation with Amplatzer vascular plugs II and IV in the treatment of dogs with splenophrenic shunts: four cases (2019-2022)

OBJECTIVES

To describe the treatment of four dogs with splenophrenic shunts using percutaneous shunting vessel embolisation with Amplatzer vascular plugs II and IV and provide information on their clinical outcomes.

MATERIALS AND METHODS

Dogs with splenophrenic shunts treated at a veterinary hospital from January 2019 to December 2022 were identified through a medical record search.

RESULTS

Six dogs with splenophrenic shunts were identified. Two dogs were excluded because they were treated with laparoscopic surgery. Four underwent percutaneous shunting vessel embolization with Amplatzer vascular plugs and were included in the case series. A sheath was placed in the left external jugular vein and a balloon catheter was advanced to the shunting vessel under fluoroscopy. Portal vein pressure was confirmed to be within an acceptable range during temporary balloon occlusion. Based on preoperative CT angiography and intraoperative contrast examination, Amplatzer vascular plugs II were selected for two dogs and IV were selected for two dogs. Under fluoroscopy, the plug was deployed into the shunting vessel, and angiography confirmed occlusion. In all cases, the increase in portal pressure after temporary occlusion was within the acceptable range, and complete occlusion of blood flow was possible with a single plug. There were no major procedure-related complications. No dogs developed post-ligation seizures or signs of portal hypertension. In addition, improvements in ammonia values were observed in all cases.

CLINICAL SIGNIFICANCE

Percutaneous splenophrenic shunt embolisation using Amplatzer vascular plugs II and IV is technically feasible in dogs, and assessed by intra-procedure angiography, a single plug completely obstructed blood flow in all dogs. Based on the literature search, this is the first report describing Amplatzer vascular plugs for the treatment of splenophrenic shunts.

Cellular senescence induction leads to progressive cell death via the INK4a-RB pathway in naked mole-rats

Naked mole-rats (NMRs) have exceptional longevity and are resistant to age-related physiological decline and diseases. Given the role of cellular senescence in aging, we postulated that NMRs possess unidentified species-specific mechanisms to prevent senescent cell accumulation. Here, we show that upon induction of cellular senescence, NMR fibroblasts underwent delayed and progressive cell death that required activation of the INK4a-retinoblastoma protein (RB) pathway (termed "INK4a-RB cell death"), a phenomenon not observed in mouse fibroblasts. Naked mole-rat fibroblasts uniquely accumulated serotonin and were inherently vulnerable to hydrogen peroxide (H2 O2 ). After activation of the INK4a-RB pathway, NMR fibroblasts increased monoamine oxidase levels, leading to serotonin oxidization and H2 O2 production, which resulted in increased intracellular oxidative damage and cell death activation. In the NMR lung, induction of cellular senescence caused delayed, progressive cell death mediated by monoamine oxidase activation, thereby preventing senescent cell accumulation, consistent with in vitro results. The present findings indicate that INK4a-RB cell death likely functions as a natural senolytic mechanism in NMRs, providing an evolutionary rationale for senescent cell removal as a strategy to resist aging.

NSUN3-mediated mitochondrial tRNA 5-formylcytidine modification is essential for embryonic development and respiratory complexes in mice

In mammalian mitochondria, translation of the AUA codon is supported by 5-formylcytidine (f⁵C) modification in the mitochondrial methionine tRNA anticodon. The 5-formylation is initiated by NSUN3 methylase. Human NSUN3 mutations are associated with mitochondrial diseases. Here we show that Nsun3 is essential for embryonic development in mice with whole-body Nsun3 knockout embryos dying between E10.5 and E12.5. To determine the functions of NSUN3 in adult tissue, we generated heart-specific Nsun3 knockout (Nsun3^HKO) mice. Nsun3^HKO heart mitochondria were enlarged and contained fragmented cristae. Nsun3^HKO resulted in enhanced heart contraction and age-associated mild heart enlargement. In the Nsun3^HKO hearts, mitochondrial mRNAs that encode respiratory complex subunits were not down regulated, but the enzymatic activities of the respiratory complexes decreased, especially in older mice. Our study emphasizes that mitochondrial tRNA anticodon modification is essential for mammalian embryonic development and shows that tissue-specific loss of a single mitochondrial tRNA modification can induce tissue aberration that worsens in later adulthood.

The Naked Mole-Rat as a Model for Healthy Aging

Naked mole-rats (NMRs, Heterocephalus glaber) are the longest-lived rodents with a maximum life span exceeding 37 years. They exhibit a delayed aging phenotype and resistance to age-related functional decline/diseases. Specifically, they do not display increased mortality with age, maintain several physiological functions until nearly the end of their lifetime, and rarely develop cancer and Alzheimer's disease. NMRs live in a hypoxic environment in underground colonies in East Africa and are highly tolerant of hypoxia. These unique characteristics of NMRs have attracted considerable interest from zoological and biomedical researchers. This review summarizes previous studies of the ecology, hypoxia tolerance, longevity/delayed aging, and cancer resistance of NMRs and discusses possible mechanisms contributing to their healthy aging. In addition, we discuss current issues and future perspectives to fully elucidate the mechanisms underlying delayed aging and resistance to age-related diseases in NMRs.

Carcinogenesis resistance in the longest-lived rodent, the naked mole-rat

Certain mammalian species are resistant to cancer, and a better understanding of how this cancer resistance arises could provide valuable insights for basic cancer research. Recent technological innovations in molecular biology have allowed the study of cancer-resistant mammals, despite the fact that they are not the classical model animals, which are easily studied using genetic approaches. Naked mole-rats (NMRs; Heterocephalus glaber) are the longest-lived rodent, with a maximum lifespan of more than 37 years, and almost never show spontaneous carcinogenesis. NMRs are currently attracting much attention from aging and cancer researchers, and published studies on NMR have continued to increase over the past decade. Cancer development occurs via multiple steps and involves many biological processes. Recent research on the NMR as a model for cancer resistance suggests that they possess various unique carcinogenesis-resistance mechanisms, including efficient DNA repair pathways, cell-autonomous resistance to transformation, and dampened inflammatory response. Here, we summarize the molecular mechanisms of carcinogenesis resistance in NMR, which have been uncovered over the past two decades, and discuss future perspectives.

Species-specific formation of paraspeckles in intestinal epithelium revealed by characterization of NEAT1 in naked mole-rat

Paraspeckles are mammalian-specific nuclear bodies built on the long noncoding RNA NEAT1_2 The molecular mechanisms of paraspeckle formation have been mainly studied using human or mouse cells, and it is not known if the same molecular components are involved in the formation of paraspeckles in other mammalian species. We thus investigated the expression pattern of NEAT1_2 in naked mole-rats (nNEAT1_2), which exhibit extreme longevity and lower susceptibility to cancer. In the intestine, nNEAT1_2 is widely expressed along the entire intestinal epithelium, which is different from the expression of mNeat1_2 that is restricted to the cells of the distal tip in mice. Notably, the expression of FUS, a FET family RNA binding protein, essential for the formation of paraspeckles both in humans and mice, was absent in the distal part of the intestinal epithelium in naked mole-rats. Instead, mRNAs of other FET family proteins EWSR1 and TAF15 were expressed in the distal region. Exogenous expression of these proteins in Fus-deficient murine embryonic fibroblast cells rescued the formation of paraspeckles. These observations suggest that nNEAT1_2 recruits a different set of RNA binding proteins in a cell type-specific manner during the formation of paraspeckles in different organisms.

Resistance to chemical carcinogenesis induction via a dampened inflammatory response in naked mole-rats

Naked mole-rats (NMRs) have a very low spontaneous carcinogenesis rate, which has prompted studies on the responsible mechanisms to provide clues for human cancer prevention. However, it remains unknown whether and how NMR tissues respond to experimental carcinogenesis induction. Here, we show that NMRs exhibit extraordinary resistance against potent chemical carcinogenesis induction through a dampened inflammatory response. Although carcinogenic insults damaged skin cells of both NMRs and mice, NMR skin showed markedly lower immune cell infiltration. NMRs harbour loss-of-function mutations in RIPK3 and MLKL genes, which are essential for necroptosis, a type of necrotic cell death that activates strong inflammation. In mice, disruption of Ripk3 reduced immune cell infiltration and delayed carcinogenesis. Therefore, necroptosis deficiency may serve as a cancer resistance mechanism via attenuating the inflammatory response in NMRs. Our study sheds light on the importance of a dampened inflammatory response as a non-cell-autonomous cancer resistance mechanism in NMRs.

Naked mole rats are found to be resistant to cancer development through dampened inflammatory response due to genetically determined impaired necroptosis, with essential necroptosis genes RIPK3 and MLKL containing mutations causing premature stop codons.

The naked truth: a comprehensive clarification and classification of current 'myths' in naked mole-rat biology

The naked mole-rat (Heterocephalus glaber) has fascinated zoologists for at least half a century. It has also generated considerable biomedical interest not only because of its extraordinary longevity, but also because of unusual protective features (e.g. its tolerance of variable oxygen availability), which may be pertinent to several human disease states, including ischemia/reperfusion injury and neurodegeneration. A recent article entitled 'Surprisingly long survival of premature conclusions about naked mole-rat biology' described 28 'myths' which, those authors claimed, are a 'perpetuation of beautiful, but falsified, hypotheses' and impede our understanding of this enigmatic mammal. Here, we re-examine each of these 'myths' based on evidence published in the scientific literature. Following Braude et al., we argue that these 'myths' fall into four main categories: (i) 'myths' that would be better described as oversimplifications, some of which persist solely in the popular press; (ii) 'myths' that are based on incomplete understanding, where more evidence is clearly needed; (iii) 'myths' where the accumulation of evidence over the years has led to a revision in interpretation, but where there is no significant disagreement among scientists currently working in the field; (iv) 'myths' where there is a genuine difference in opinion among active researchers, based on alternative interpretations of the available evidence. The term 'myth' is particularly inappropriate when applied to competing, evidence-based hypotheses, which form part of the normal evolution of scientific knowledge. Here, we provide a comprehensive critical review of naked mole-rat biology and attempt to clarify some of these misconceptions.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Isolation and characterization of neural stem/progenitor cells in the subventricular zone of the naked mole-rat brain

Background

The naked mole-rat (NMR) is the longest-lived rodent with a maximum lifespan of more than 37 years and shows a negligible senescence phenotype, suggesting that tissue stem cells of NMRs are highly capable of maintaining homeostasis. However, the properties of NMR tissue stem cells, including neural stem cells (NSCs), are largely unclear.

Methods

Neural stem/progenitor cells (NS/PCs) were isolated from the subventricular zone of the neonate NMR brain (NMR-NS/PCs) and cultured in neurosphere and adherent culture conditions. Expression of NSC markers and markers of neurons, astrocytes, and oligodendrocytes was analyzed by immunocytochemistry. In adherent culture conditions, the proliferation rate and cell cycle of NMR-NS/PCs were assessed and compared with those of NS/PCs from mice (mouse-NS/PCs). The DNA damage response to γ-irradiation was analyzed by immunocytochemistry and reverse transcription-quantitative PCR.

Results

NMR-NS/PCs expressed several NSC markers and differentiated into neurons, astrocytes, and oligodendrocytes. NMR-NS/PCs proliferated markedly slower than mouse-NS/PCs, and a higher percentage of NMR-NS/PCs than mouse-NS/PCs was in G0/G1 phase. Notably, upon γ-irradiation, NMR-NS/PCs exhibited a faster initiation of the DNA damage response and were less prone to dying than mouse-NS/PCs.

Conclusions

NMR-NS/PCs were successfully isolated and cultured. The slow proliferation of NMR-NS/PCs and their resistance to DNA damage may help to prevent stem cell exhaustion in the brain during the long lifespan of NMRs. Our findings provide novel insights into the mechanism underlying delayed aging of NMRs. Further analysis of NMR tissue stem cells may lead to the development of new strategies that can prevent aging in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41232-021-00182-7.

Differential biomechanical responses of elastic and muscular arteries to angiotensin II-induced hypertension

Elastic and muscular arteries are distinguished by their distinct microstructures, biomechanical properties, and smooth muscle cell contractile functions. They also exhibit differential remodeling in aging and hypertension. Although regional differences in biomechanical properties have been compared, few studies have quantified biaxial differences in response to hypertension. Here, we contrast passive and active changes in large elastic and medium- and small-sized muscular arteries in adult mice in response to chronic infusion of angiotensin over 14 days. We found a significant increase in wall thickness, both medial and adventitial, in the descending thoracic aorta that associated with trends of an increased collagen:elastin ratio. There was adventitial thickening in the small-sized mesenteric artery, but also significant changes in elastic lamellar structure and contractility. An increased contractile response to phenylephrine coupled with a reduced vasodilatory response to acetylcholine in the mesenteric artery suggested an increased contractile state in response to hypertension. Overall reductions in the calculated gradients in pulse wave velocity and elastin energy storage capability from elastic-to-muscular arteries suggested a possible transfer of excessive pulsatile energy into the small-sized muscular arteries resulting in significant functional consequences in response to hypertension.

Adventitial remodeling protects against aortic rupture following late smooth muscle-specific disruption of TGFβ signaling

Altered signaling through transforming growth factor-beta (TGFβ) increases the risk of aortic dissection in patients, which has been confirmed in mouse models. It is well known that altered TGFβ signaling affects matrix turnover, but there has not been a careful examination of associated changes in structure-function relations. In this paper, we present new findings on the rupture potential of the aortic wall following late postnatal smooth muscle cell (SMC)-specific disruption of type I and II TGFβ receptors in a mouse model with demonstrated dissection susceptibility. Using a combination of custom computer-controlled biaxial tests and quantitative histology and immunohistochemistry, we found that loss of TGFβ signaling in SMCs compromises medial properties but induces compensatory changes in the adventitia that preserve wall strength above that which is needed to resist in vivo values of wall stress. These findings emphasize the different structural defects that lead to aortic dissection and rupture - compromised medial integrity and insufficient adventitial strength, respectively. Relative differences in these two defects, in an individual subject at a particular time, likely reflects the considerable phenotypic diversity that is common in clinical presentations of thoracic aortic dissection and rupture. There is, therefore, a need to move beyond examinations of bulk biological assays and wall properties to cell- and layer-specific studies that delineate pathologic and compensatory changes in wall biology and composition, and thus the structural integrity of the aortic wall that can dictate differences between life and death.

Induced Pluripotent Stem Cells from Cancer-Resistant Naked Mole-Rats

Stem cells play essential roles in the development and tissue homeostasis of animals and are closely associated with carcinogenesis and aging. Also, the somatic cell reprogramming process to induced pluripotent stem (iPS) cells shares several characteristics with carcinogenesis. In this chapter, we focus on iPS cells and the reprogramming process of somatic cells in the naked mole-rat (NMR), the longest-living rodent with remarkable cancer resistance capabilities. NMR somatic cells show resistance to reprogramming induction, and generated NMR-iPS cells have a unique tumor-resistant phenotype. This phenotype is regulated by expressional activation of the tumor suppressor ARF gene and loss-of-function mutation in oncogene ERAS. Notably, it was also found that NMR somatic cells undergo senescence when ARF is suppressed during reprogramming, which would contribute to the resistance to both reprogramming and cancer in NMR somatic cells. Further studies on reprogramming resistance in NMR somatic cells and their concomitant tumor resistance in NMR-iPS cells would contribute to a better understanding of both cancer resistance and delayed aging in NMRs. In addition, NMR-iPS cells can be used as a new and important cell source for advancing research concerning several extraordinary physiological characteristics of NMR. Furthermore, study of NMR-iPS cells could lead to the development of safer regenerative therapies in the future.

FZD5 regulates cellular senescence in human mesenchymal stem/stromal cells

Human mesenchymal stem/stromal cells (hMSCs) have garnered enormous interest as a potential resource for cell‐based therapies. However, the molecular mechanisms regulating senescence in hMSCs remain unclear. To elucidate these mechanisms, we performed gene expression profiling to compare clonal immature MSCs exhibiting multipotency with less potent MSCs. We found that the transcription factor Frizzled 5 (FZD5) is expressed specifically in immature hMSCs. The FZD5 cell surface antigen was also highly expressed in the primary MSC fraction (LNGFR⁺THY‐1⁺) and cultured MSCs. Treatment of cells with the FZD5 ligand WNT5A promoted their proliferation. Upon FZD5 knockdown, hMSCs exhibited markedly attenuated proliferation and differentiation ability. The observed increase in the levels of senescence markers suggested that FZD5 knockdown promotes cellular senescence by regulating the noncanonical Wnt pathway. Conversely, FZD5 overexpression delayed cell cycle arrest during the continued culture of hMSCs. These results indicated that the intrinsic activation of FZD5 plays an essential role in negatively regulating senescence in hMSCs and suggested that controlling FZD5 signaling offers the potential to regulate hMSC quality and improve the efficacy of cell‐replacement therapies using hMSCs.

Characterizing genetic variants for DAG and IP3 signalling pathways in severe cases of coronary spastic angina

Background

We previously reported that the activity of phospholipase C (PLC), a key molecule for intracellular calcium signaling, was enhanced in patients with coronary spastic angina (CSA). Furthermore, we found PLC-δ1 864 G to A mutation in about 10% of the male CSA patients. However, comprehensive understanding of genetic role in the pathogenesis of CSA remains to be elucidated.

Purpose

We tested the hypothesis that variants in the genes responsible for contraction signaling, especially a Ca2+-dependent mechanism, plays an important role in the pathogenesis of CSA.

Methods and results

Exome sequencing was performed to genotype comprehensively CSA cohort, enabling investigation of 258 gene network for diacylglycerol (DAG) and inositol trisphosphate (IP3) signallings, which are responsible for contraction signaling in the vascular smooth muscle cell (VSMC) by a Ca2+-dependent mechanism.

The study population included 30 Japanese patients with severe cases of CSA (18 men and 12 women with a mean age of 62.2±10.1 years). In 23 patients, ST segment elevation was recorded on the electrocardiogram during a spontaneous attack. In other 3 patients, ventricular fibrillation occurred following CSA attacks. The rests were diagnosed by ECG changes and elevated cardiac enzymes following CSA attacks. Genetic information from these CSA patients were compared with those from 914 healthy controls.

Frequencies of 17 common, functional polymorphisms of DAG and IP3 signallings were statistically similar to those of healthy controls. By high-quality (Call Quality ≥20, Read Depth ≥10), and predicted-deleterious (CADD score ≥20) filterings, the number of the candidate genes were narrowed from 234,445 to 17,738, and by selecting genes for DAG and IP3 signallings, further narrowed to 208 genes. Compared with 914 healthy controls, DAG and IP3 signalling genes revealed 26 variants in 15 genes in CSA cases, and by further filtering for rare (914 healthy control frequency <1%), 21 variants in 12 genes were found. They shared variants in G protein subunit alpha q (GNAQ), phospholipase C beta 3 (PLCB3), inositol 1,4,5-trisphosphate receptor type 3 (ITPR3), glutamate ionotropic receptor NMDA type subunit 2D (GRIN2D) in ≥5 cases. By filtering for high-quality, predicted-deleterious, and rare, genetic variants related with DAG and IP3 signalling were more found in severe CSA patients compared with healthy controls (CSA 4.33/person vs healthy controls 2.60 /person).

Conclusions

These findings indicate genetic heterogeneity in CSA susceptibility and a likely polygenic basis, giving a cumulative effect on DAG and IP3 signalling pathways in a subset of individual CSA patients. Study of larger cohorts is warranted to define genetic risk factors for CSA.

Funding Acknowledgement

Type of funding source: None

Paradoxical aortic stiffening and subsequent cardiac dysfunction in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare disorder with devastating sequelae resulting in early death, presently thought to stem primarily from cardiovascular events. We analyse novel longitudinal cardiovascular data from a mouse model of HGPS (Lmna^G609G/G609G) using allometric scaling, biomechanical phenotyping, and advanced computational modelling and show that late-stage diastolic dysfunction, with preserved systolic function, emerges with an increase in the pulse wave velocity and an associated loss of aortic function, independent of sex. Specifically, there is a dramatic late-stage loss of smooth muscle function and cells and an excessive accumulation of proteoglycans along the aorta, which result in a loss of biomechanical function (contractility and elastic energy storage) and a marked structural stiffening despite a distinctly low intrinsic material stiffness that is consistent with the lack of functional lamin A. Importantly, the vascular function appears to arise normally from the low-stress environment of development, only to succumb progressively to pressure-related effects of the lamin A mutation and become extreme in the peri-morbid period. Because the dramatic life-threatening aortic phenotype manifests during the last third of life there may be a therapeutic window in maturity that could alleviate concerns with therapies administered during early periods of arterial development.

Mechanical feedback cooling assisted by optical cavity cooling of the thermal vibration of a microcantilever

This study describes a new two-step process to cool the thermal vibration of microcantilevers. The process combines active mechanical feedback cooling and optical cavity cooling. A micro-Fabry–Perot interferometer, built in-house, is set atop a microcantilever to measure the vibration amplitude, the high optical power density of which induces cavity cooling in the optical cavity. Using a two-step cooling procedure, the equivalent temperature of the thermal vibration of a microcantilever is lowered from room temperature to the theoretical cooling limit of 0.063 K, a much lower temperature than that achieved via simple cavity cooling (18 K), and then by mechanical feedback cooling (0.135 K) obtained for the same type of microcantilevers in previous studies. This experimental demonstration showcases a new type of cooling process of the amplitude of thermal vibration for micro-mechanical resonators to a lower temperature and does not need additional cooling using a conventional cryogenic refrigerator.

Flow cytometric identification and cell-line establishment of macrophages in naked mole-rats

Naked mole rats (NMRs) have extraordinarily long lifespans and anti-tumorigenic capability. Recent studies of humans and mice have shown that many age-related diseases, including cancer, are strongly correlated with immunity, and macrophages play particularly important roles in immune regulation. Therefore, NMR macrophages may contribute to their unique phenotypes. However, studies of the roles of macrophages are limited by material restrictions and the lack of an established experimental strategy. In this study, we developed a flow cytometric strategy to identify NMR macrophages. The NMR macrophages were extractable using an off-the-shelf anti-CD11b antibody, M1/70, and forward/side scatter data obtained by flow cytometry. NMR macrophages proliferated in response to human/mouse recombinant M-CSF and engulfed Escherichia coli particles. Interestingly, the majority of NMR macrophages exhibited co-staining with an anti-NK1.1 antibody, PK136. NK1.1 antigen crosslinking with PK136 results in mouse NK cell stimulation; similarly, NMR macrophages proliferated in response to NK1.1 antibody treatment. Furthermore, we successfully established an NMR macrophage cell line, NPM1, by transduction of Simian virus 40 early region that proliferated indefinitely without cytokines and retained its phagocytotic capacity. The NPM1 would contribute to further studies on the immunity of NMRs.

P838Is multi-biomarker combination approach comparable to the GRACE risk score for short-term mortality prediction in acute myocardial infarction cases?

Introduction

The Global Registry of Acute Coronary Events (GRACE) score is said to be a superior predictor of mortality in acute myocardial infarction (AMI) patients, and same applies to biochemical parameters as N-terminal pro-B-type natriuretic peptide (N-BNP), Troponin-T (TnT) and high-sensitivity C- reactive protein (hs-CRP) levels.

Purpose

We validated that whether each or combination of biochemical parameters are comparable to GRACE score or not for mortality prediction in AMI patients.

Method

We investigated about clinical background including The GRACE score, above parameters and in-hospital mortality in 754 AMI patients (mean age 66±13y/o, 609 ST-elevated AMI cases) received emergency percutaneous coronary intervention (PCI) successfully during 8 years in a single center retrospectively. Combination of biochemical parameters are derived from N-BNP, TnT and hs-CRP by logistic regression analyses. We compared The GRACE score with each or combination of biochemical parameters between survival (SG) and non-survival group (nSG) on receiver operating characteristic (ROC) analysis.

Result

In-hospital mortality was 6.8%. The GRACE score (106±33 versus 161±32; p<0.005) and N-BNP level (2458±7058 versus 8880±11331pg/ml; p<0.005) were significantly lower in SG than nSG. Area under the ROC curve about in-hospital mortality of The GRACE score were higher (0.868) than N-BNP (0.787; p=0.007), TnT (0.613; p<0.005), hs-CRP levels (0.614; p<0.005) and multi-biomarker combination (0.742; p=0.016) as Figure 1.

Area under the curve of the composite with the GRACE score and multi-biomarker is not increased compared with the GRACE score alone (0.868 versus 0.865; p=n.s.).

Figure 1

Conclusion

The GRACE score is a superior predictor about in-hospital mortality than each or combination of biochemical parameters in AMI patients. Multi-biomarker combination dose not refine the accuracy of the GRACE score.

P1624Blockade of protease activated receptor-1 signaling attenuates cardiac hypertrophy and fibrosis in renin-overexpressing hypertensive mice

Introduction

Recent evidences have demonstrated that coagulation pathway is involved in cardiovascular remodeling induced by renin-angiotensin system (RAS), which finally leads to heart failure. Protease activated receptor-1 (PAR-1) is widely expressed in the vasculature and the heart, and plays important roles in pro-inflammatory process in the cardiovascular system. Recently, we demonstrated that the activity of factor Xa (FXa), which functions not only as a coagulation factor but as an agonist for PAR-1, was enhanced in renin-overexpressing hypertensive mice (Ren-Tg).

Purpose

The purpose of this study was to investigate whether inhibition of PAR-1 signaling has protective effects on the progression of heart failure induced by chronic RAS activation in Ren-Tg.

Methods and results

We treated 12–16 weeks-old male wild type mice (WT) and Ren-Tg with continuous subcutaneous infusion of PAR-1 antagonist SCH79797 (25mg/kg/day) or vehicle for 4 weeks. After treatment period, left ventricular (LV) wall thickness calculated as interventricular septum plus posterior wall thickness measured by echocardiography was greater in Ren-Tg than in WT (0.25±0.003 versus 0.18±0.002 mm), and SCH79797 attenuated the increase to 0.22±0.01 mm in Ren-Tg (both p<0.05, respectively). The ratio of heart weight to body weight was greater in Ren-Tg than in WT (6.1±0.4 versus 4.6±0.7 mg/g), and SCH79797 attenuated the increase to 5.2±0.1 mg/g (both p<0.05). The area of cardiac fibrosis evaluated by Masson-trichrome staining was greater in Ren-Tg than in WT (2.6±0.2 versus 1.4±0.3%), and SCH79797 attenuated it to 1.6±0.3% in Ren-Tg (both p<0.05). Cardiac mRNA expressions of tumor necrosis factor-α, transforming growth factor-β1, and β-myosin heavy chain were all greater in Ren-Tg than in WT, and SCH79797 attenuated the increases in Ren-Tg (all p<0.05).

Conclusions

Inhibition of PAR-1 signaling attenuates cardiac hypertrophy and fibrosis in Ren-Tg via inhibition of inflammatory cytokines production. These results support the involvement of PAR signaling in the development of heart failure induced by RAS, and may provide novel therapeutic insights for the treatment of hypertensive heart failure.

The Role of Oral Kinesthesia in the Determination of the Swallowing Threshold

The interdental dimension discrimination (IDD) ability and the swallowing threshold were evaluated at the sitting and supine positions. The difference in the magnitude of mis-estimation of IDD and that in the swallowing threshold between the two positions was significantly correlated. These results indicate some influence of the IDD in the determination of the swallowing threshold.

Temporomandibular Joint Movement

Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy.

Long-term entecavir therapy results in falls in serum hepatitis B surface antigen levels and seroclearance in nucleos(t)ide-naïve chronic hepatitis B patients

Entecavir (ETV) is reported to result in suppression of hepatitis B virus DNA (HBV DNA) replication with minimal drug resistance. However, information on the long-term effect of such therapy on serum hepatitis B surface antigen (HBsAg) level and elimination of HBsAg is not available. ETV therapy was started in 553 nucleos(t)ide-naïve patients with chronic hepatitis B infection (HBeAg positive: 45%) in our hospital. Serum HBsAg levels were measured serially by the Architect assay. The median baseline HBsAg was 2180 IU/mL (0.12-243 000 IU/mL), and median follow-up period was 3.0 years, with 529, 475, 355, 247 and 163 patients followed-up for 1, 2, 3, 4 and 5 years, respectively. At year 5, the mean log HBsAg decline from baseline was -0.48 log IU/mL, and the cumulative HBsAg clearance rate was 3.5%. Multivariate analysis identified HBV DNA level at baseline (<3.0 log copies IU/mL, odd ratio = 10.2; 95% confidence interval = 1.87-55.5, P = 0.007) and HBsAg level (<500 IU/mL, odd ratio = 29.4; 95% confidence interval = 2.80-333, P = 0.005) as independent predictors of HBsAg seroclearance. These results indicate that although serum HBsAg level declines gradually during ETV therapy, HBsAg seroclearance remains a rare event.