Bepridil Inhibits Premature Ventricular Complexes Induced by Cardio-Sympathetic Nerve Stimulation in a Canine Experimental Model

Sympathetic nerve activity has arrhythmogenic potential for ventricular arrhythmias associated with structural heart diseases. However, a sufficient amount of beta-blockers occasionally cannot be prescribed in some patients.An experimental study was performed to clarify the therapeutic effects of bepridil, a multiple ionic current inhibitor that does not affect beta-adrenergic receptors, for premature beats occurring during enhanced sympathetic nerve activity. Cardio-sympathetic nerve activity was augmented via stellate-ganglion (SG) stimulation in a canine model (n = 8), and the arrhythmogenic potential and anti-arrhythmic effects of bepridil (2 and 4 mg/kg intravenously) were assessed. For safe use, vagal-stimulation-induced slow HR and programmed electrical stimulation were applied to evaluate possible pro-arrhythmic effects of the drug. Heart rate variability (HRV) indexes were used to estimate cardio-autonomic nerve activity.Either side of the SG-stimulation increased BP and HR. Premature beats were induced in 10/16 SG-stimulations and it was more frequent in left (8/8) rather than right stimulation (2/8). Following 2 mg/kg drug administration, premature beats were still inducible in 8/16 stimulations (7/8 in left and 1/8 in right), but burden of the premature beats decreased from 87.1 ± 46.8 to 62.1 ± 42.6 beats. After 4 mg/kg administration, premature beats were inducible in one SG-stimulation. Proarrhythmic effects were not observed in all experiments. Steady-state HRV indexes and percent increases in SG-stimulation-induced BP-elevation and HR-acceleration were similar among the 3 periods (before, 2 and 4 mg/kg of the drug).Bepridil may be an option for ventricular arrhythmias developed during enhanced cardio-sympathetic nerve activity with minimal effect on autonomic nerve responses.

Extracellular Vesicles of Stem Cells to Prevent BRONJ

Extracellular vesicles (EVs), several tens to hundreds of nanometers in size, are vesicles secreted by cells for intercellular communication. EVs released from mesenchymal stem cells (MSC-EVs) have the potential to treat multiple diseases. This study aimed to determine the effects of MSC-EVs on bisphosphonate-related osteonecrosis of the jaw (BRONJ), whose pathogenesis and treatment are not yet established. To this end, zoledronic acid (ZOL) was administered to bone marrow cells and fibroblasts in vitro. In vivo, a BRONJ model was produced by administering ZOL to rats and extracting teeth. Each MSC-EV-treated and nontreated group was compared histologically and molecularly. In vitro, the nontreated group showed an increased number of β-galactosidase-positive cells and expression of senescence-associated genes p21, pRB and senescence-related inflammatory cytokines. Conversely, MSC-EV administration decreased the number of senescent cells and expression levels of p21, pRB and inflammatory cytokines. In vivo, in the nontreated group, the socket was partially uncovered by the oral epithelium, leaving an exposed bone. Conversely, in the MSC-EV-treated group, the socket was healed. Besides, in the nontreated group, β-galactosidase-positive cells existed in the socket and colocalized with the CD90 and periostin-positive cells. However, there were few β-galactosidase-positive cells in the MSC-EV-treated group. Furthermore, gene expression of stem cell markers Bmi1 and Hmga2 and the vascular endothelial marker VEGF was significantly increased in the MSC-EV-treated group, compared with that in the nontreated group. These results indicate that MSC-EVs prevent ZOL-induced senescence in stem cells, osteoblasts, and fibroblasts and reduce inflammatory cytokines. Furthermore, administration of MSC-EVs prevented senescence of cells involved in wound healing and the spread of chronic inflammation around senescent cells, thereby promoting angiogenesis and bone regeneration and preventing BRONJ.

Therapy-Resistant Ventricular Arrhythmias Developed More Often in Advanced Than in Therapeutic Mild Hypothermic Condition

Therapy-resistant ventricular arrhythmias can occur during accidental advanced hypothermic conditions. On the other hand, hypothermic therapy using mild cooling has been successfully accomplished with infrequent ventricular arrhythmia events.To further clarify the therapeutic-resistant arrhythmogenic substrate which develops in hypothermic conditions, an experimental study was performed using a perfusion wedge preparation model of porcine ventricle, and electrophysiological characteristics, inducibility of ventricular arrhythmias, and effects of therapeutic interventions were assessed at 3 target temperatures (37, 32 and 28°C).As the myocardial temperature decreased, myocardial contractions and the number of spontaneous beats deceased. Depolarization (QRS width, stimulus-QRS interval) and repolarization (QT interval, ERP) parameters progressively increased, and dispersion of the ventricular repolarization increased. At 28°C, VF tended to be inducible more frequently (1/11 at 37°C, 1/11 at 32°C, and 5/11 hearts at 28°C), and some VFs at 28°C required greater defibrillation energy to resume basic rhythm.An advanced but not a mild hypothermic condition had an enhanced arrhythmogenic potential in our model. In the advanced hypothermic condition, VF with relatively prolonged F-F intervals and a greater defibrillation energy were occasionally inducible based on the arrhythmogenic substrate characterized as slowed conduction and prolonged repolarization of the ventricle.

Occurrence and fate of endotoxin activity at drinking water purification plants and healthcare facilities in Japan

Occurrence of residual endotoxin activity (ET) in dialysis water and also tap water as its source is a matter of great concern to medical professionals conducting dialysis therapy at healthcare facilities (HCFs). The present study was performed to determine the occurrence and fate of the ET at selected Japanese drinking water purification plants and HCFs between 2014 and 2016. Chemical coagulation and sedimentation, rapid sand filtration, and membrane filtration were highly effective to decrease both ET dissolved in water (free-ET) and ET bound to cells/particles (bound-ET). Moderate decreases in bound-ET and limited decreases in free-ET were observed by chlorination and ozonation. Bacterial activated carbon filtration was a major cause of significant increases in endotoxin activity during the course of drinking water purification process. Levels of residual ET in water supplied to HCFs were strongly affected by their source waters and the configurations of water purification processes served. Microbial regrowth on the premises, from water tanks to faucets at HCFs could also contribute to ET increases in tap water.

Clade-specific evolutionary diversification along ontogenetic major axes in avian limb skeleton

The evolutionary diversification of birds has been facilitated by specializations for various locomotor modes, with which the proportion of the limb skeleton is closely associated. However, recent studies have identified phylogenetic signals in this system, suggesting the presence of historical factors that have affected its evolutionary variability. In this study, to explore potential roles of ontogenetic integration in biasing the evolution in the avian limb skeleton, evolutionary diversification patterns in six avian families (Anatidae, Procellariidae, Ardeidae, Phalacrocoracidae, Laridae, and Alcidae) were examined and compared to the postnatal ontogenetic trajectories in those taxa, based on measurement of 2641 specimens and recently collected ontogenetic series, supplemented by published data. Morphometric analyses of lengths of six limb bones (humerus, ulna, carpometacarpus, femur, tibiotarsus, and tarsometatarsus) demonstrated that: (1) ontogenetic trajectories are diverse among families; (2) evolutionary diversification is significantly anisotropic; and, most importantly, (3) major axes of evolutionary diversification are correlated with clade-specific ontogenetic major axes in the shape space. These results imply that the evolutionary variability of the avian limbs has been biased along the clade-specific ontogenetic trajectories. It may explain peculiar diversification patterns characteristic to some avian groups, including the long-leggedness in Ardeidae and tendency for flightlessness in Anatidae.

Correction: Myeloproliferative leukemia protein activation directly induces fibrocyte differentiation to cause myelofibrosis

Owing to the insufficient specificity of the anti-myeloproliferative leukemia protein (MPL) antibody in the original version of this Article, Figure 6 and parts of Figures 2a, 4e, and 5a do not represent the correct information. The corrected version of Figure 6 is in this correction and those of Figures 2a, 4e, and 5a are shown in the supplemental information.

Randomized clinical trial of high versus low inferior mesenteric artery ligation during anterior resection for rectal cancer

BACKGROUND

The optimal level for inferior mesenteric artery ligation during anterior resection for rectal cancer is controversial. The aim of this randomized trial was to clarify whether the inferior mesenteric artery should be tied at the origin (high tie) or distal to the left colic artery (low tie).

METHODS

Patients were allocated randomly to undergo either high- or low-tie ligation and were stratified by surgical approach (open or laparoscopic). The primary outcome was the incidence of anastomotic leakage. Secondary outcomes were duration of surgery, blood loss and 5-year overall survival.

RESULTS

Some 331 patients entered the trial between June 2006 and September 2012. The trial was stopped prematurely as recruitment was slow. Seven patients were excluded after randomization but before operation because of procedural changes. High tie and low tie were performed in 164 and 160 patients respectively. The incidence of anastomotic leakage was not significantly different (17·7 versus 16·3 per cent respectively; P = 0·731). The incidence of severe complications requiring intervention was 2·4 versus 5·0 per cent for high and low tie respectively (P = 0·222). In multivariable analysis, risk factors for anastomotic leakage included male sex (odds ratio 4·36, 95 per cent c.i. 1·56 to 12·18) and distance of the tumour from the anal verge (odds ratio 0·99, 0·98 to 1·00). At 5 years there were no significant differences in overall (87·2 versus 89·4 per cent respectively; P = 0·386) and disease-free (76·3 versus 77·6 per cent; P = 0·765) survival.

CONCLUSION

The level of ligation of the inferior mesenteric artery does not significantly influence the rate of anastomotic leakage. Registration number: NCT01861678 ( https://clinicaltrials.gov).

Effect of Vitamin E on Platelet Aggregation in Diabetes Mellitus

Vitamin E is known to be an inhibitor of platelet prostaglandin production and aggregation. The rate of platelet aggregation induced by adenosine diphosphate was significantly increased in diabetics with proliferative retinopathy and the enhanced production of thromboxane B2, a stable metabolite of thromboxane A2, was demonstrated in those patients. On the other hand, vitamin E in platelets was significantly reduced in diabetics compared with age matched controls. In addition, it was shown that vitamin E content in platelets examined in diabetic and control subjects inversely correlated with both the rate of platelet aggregation and thromboxane B2 production during aggregation. It is suggested that the reduced vitamin E levels in diabetic platelets can contribute to the mechanisms of the enhanced platelet thromboxane production and aggregation which relate to the development of vascular complications.

Abstract P1-17-09: Leptomeningeal disease in ER+HER2- metastatic breast cancer patients: A review of the cases in a single institute over a 14-year period

Background: Leptomeningeal disease (LMD) is a pattern of central nervous system (CNS) metastasis that occurs in metastatic breast cancer (MBC) patients (pts). Some reports have revealed that it occurs more frequently in pts with estrogen receptor-positive (ER+), HER2-MBC than in pts with other subtypes. However, in such ER+HER2-MBC pts, LMD mainly occurs in the terminal stage of the disease; thus, the details of LMD have not been well described.

Methods: We reviewed the medical records of ER+HER2-MBC pts who were treated from 2002 to present, with the aim of assessing the incidence, background and outcomes of LMD. Statistical analyses were performed using the chi-squared test, Kaplan-Meyer method, log-rank test and a multivariate COX regression analysis.

Results: We identified a total of 369 ER+HER2-MBC pts, and 102 (27.6%) developed CNS metastasis. LMD developed in 32 (8.7%) pts, with the median time to LMD of 778 days (95% confidence interval [CI] 335-1221; range 0-3757 days) from the diagnosis of MBC. In most cases (28, 87.5%), LMD was accompanied by bone metastasis, and 24 pts (75.0%) showed metastasis to the skull. Thirteen pts (40.6%) had accompanying brain metastasis (BM) at the diagnosis of LMD. The majority of the pts had symptoms (25, 78.1%), and their accompanying extra-CNS lesions showed progression (23, 71.9%). Palliative radiotherapy (RT) was introduced in 27 pts (84.4%), with 4 pts (12.5%) receiving whole CNS RT. The intrathecal injection of methotrexate was introduced to one patient. The median overall survival (OS) from the diagnosis of LMD was 104 days (95% CI 38-170); however, when limited to pts without BM (N = 19), the median OS was 146 days (95%CI 79-213). All of the pts died, and the causes of death were as follows: CNS lesion progression, n=10 (31.3%); cachexia, n=9 (28.1%); respiratory failure, n=8 (25.0%); hepatic failure, n=4 (12.5%) and infection, n=1 (3.1%). There was no significant relationship between the time to LMD and OS after the diagnosis of LMD (Spearman's ρ=0.55, not significant). The multivariate analysis did not reveal any specific factors—such as the patient age, the presence of any symptom(s) at the diagnosis of LMD, the distribution of extra-CNS lesion(s) or the control of extra-CNS lesion(s)—that affected OS after the diagnosis of LMD.

As a control, 70 ER+HER2-MBC pts who developed BM without LMD (BM-only group) within the same observation period were analyzed. The median time to BM was 611 days (95%CI 404-818), and it did not differ from that of pts with LMD (LMD-group) to a statistically significant extent (P >0.1). The BM-only group showed superior OS after the diagnosis of their CNS lesions in comparison to LMD-group (median, 295 days and 104 days, respectively, P <0.001). At the diagnosis of the CNS lesion, the LMD-group showed a higher rate of CNS symptoms (P <0.01), a lower rate of liver metastasis (P <0.05), a higher rate of bone metastasis (P <0.05) and a higher rate of skull metastasis (P < 0.01).

Conclusion: Our retrospective analysis at a single institute revealed that the prognosis of LMD in pts with ER+HER2-MBC was still extremely poor. The data suggest that LMD is distinct from BM in terms of its pathology and response to therapy.

Citation Format: Watanabe J, Mitsuya K, Hayashi N, Nakasu Y. Leptomeningeal disease in ER+HER2- metastatic breast cancer patients: A review of the cases in a single institute over a 14-year period [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-17-09.

Ontogeny of Surface Texture of Limb Bones in Modern Aquatic Birds and Applicability of Textural Ageing

Despite its importance in various disciplines, a general method to assess ontogenetic ages of skeletal and fossil specimens has been lacking for birds. Although the textural ageing method was formulated to assess relative ontogenetic ages of specimens from inspection of bone surface textures, the exact correspondence of surface textures to ontogenetic stages has not yet been clear. In this study, bone surface textures of six major limb bones (humerus, ulna, carpometacarpus, femur, tibiotarsus, and tarsometatarsus) were described in postnatal ontogenies of four species of modern birds (Calonectris leucomelas, Phalacrocorax capillatus, Larus crassirostris, and Cerorhinca monocerata) from 14 to 28 individuals of known ontogenetic stages for each species. Consistently with the previous postulation, it was found that bones of chicks were characterized by rough surface textures with numerous grooves/depressions that host minute foramina. Bones of fledglings/juveniles, which are generally as large as those of adults but more slender, were characterized by the occasional presence of depressions and foramina. Histological observations confirmed that these rough surface textures were underlain by fibrolamellar bone tissue which is associated with active periosteal ossification. These results indicate that the smooth surface texture in adults is formed after the cessation of circumferential bone growth, which probably takes place between fledging and the attainment of sexual maturity. The available evidence suggests that the textural ageing is probably applicable to the entire Neognathae, a clade containing most crown-group birds. Anat Rec, 301:1026-1045, 2018. © 2017 Wiley Periodicals, Inc.

Influence of food on the gastric motor effect of the Kampo medicine rikkunshito in rat

BACKGROUND

Rikkunshito, one of the Kampo medicines, is widely prescribed as a remedy for various upper gastrointestinal syndromes. The effect of rikkunshito is related to endogenous ghrelin and its active ingredient atractylodin enhances ghrelin receptor signaling. Kampo medicines are traditionally administered before or between meals; however, no definitive benefit of the timing of administration has been proven yet. To clarify the influence of food on the pharmacological action of rikkunshito, we investigated the gastric motor activity and pharmacokinetic profiles of atractylodin after the administration of rikkunshito in fasted and fed rats.

METHODS

Phase III-like contractions in the gastric antrum after an injection of ghrelin were measured using a strain gauge force transducer. Rikkunshito was administered to rats during fasting or after a nutrient test meal. Ghrelin was injected 30 minutes later and gastric motility was evaluated. Furthermore, after rikkunshito administration, the pharmacokinetic profiles of atractylodin in the plasma and brain of fasted and free-fed rats were assessed.

KEY RESULTS

Rikkunshito administration potentiated ghrelin-induced phase III-like contractions under fasting conditions. This effect was attenuated in animals fed a test meal. Atractylodin was detected pharmacokinetically in the plasma and brain after rikkunshito administration in rats, and free-fed rats exhibited a decreased maximum concentration of plasma atractylodin and a delayed time to reach the maximum concentration.

CONCLUSIONS & INFERENCES

We show that the pharmacological action of rikkunshito is influenced by food in rats. The efficacy of rikkunshito may be associated with decreased absorption of its active ingredient atractylodin when food is in the stomach.