Skin graft with dermis and appendages generated in vivo by cell competition.

Autologous skin grafting is a standard treatment for skin defects such as burns. No artificial skin substitutes are functionally equivalent to autologous skin grafts. The cultured epidermis lacks the dermis and does not engraft deep wounds. Although reconstituted skin, which consists of cultured epidermal cells on a synthetic dermal substitute, can engraft deep wounds, it requires the wound bed to be well-vascularized and lacks skin appendages. In this study, we successfully generate complete skin grafts with pluripotent stem cell-derived epidermis with appendages on p63 knockout embryos' dermis. Donor pluripotent stem cell-derived keratinocytes encroach the embryos' dermis by eliminating p63 knockout keratinocytes based on cell-extracellular matrix adhesion mediated cell competition. Although the chimeric skin contains allogenic dermis, it is engraftable as long as autologous grafts. Furthermore, we could generate semi-humanized skin segments by human keratinocytes injection into the amnionic cavity of p63 knockout mice embryos. Niche encroachment opens the possibility of human skin graft production in livestock animals.

Home Treatment for Active Cancer Patients With Low-Risk Pulmonary Embolism　- A Predetermined Companion Report From the ONCO PE Trial.

BACKGROUND: Patients with appropriately selected low-risk pulmonary embolism (PE) can be treated at home, although it has been controversial whether applies to patients with cancer, who are considered not to be at low risk.Methods and Results: The current predetermined companion report from the ONCO PE trial evaluated the 3-month clinical outcomes of patients with home treatment and those with in-hospital treatment. The ONCO PE trial was a multicenter, randomized clinical trial among 32 institutions in Japan investigating the optimal duration of rivaroxaban treatment in cancer-associated PE patients with a score of 1 using the simplified version of the Pulmonary Embolism Severity Index (sPESI). Among 178 study patients, there were 66 (37%) in the home treatment group and 112 (63%) in the in-hospital treatment group. The primary endpoint of a composite of PE-related death, recurrent venous thromboembolism (VTE) and major bleeding occurred in 3 patients (4.6% [0.0-9.6%]) in the home treatment group and in 2 patients (1.8% [0.0-4.3%]) in the in-hospital treatment group. In the home treatment group, there were no cases of PE-related death or recurrent VTE, but major bleeding occurred in 3 patients (4.6% [0.0-9.6%]), and 2 patients (3.0% [0.0-7.2%]) required hospitalization due to bleeding events. CONCLUSIONS: Active cancer patients with PE of sPESI score=1 could be potential candidates for home treatment.

Functional calcium-responsive parathyroid glands generated using single-step blastocyst complementation.

Patients with permanent hypoparathyroidism require lifelong replacement therapy to avoid life-threatening complications, The benefits of conventional treatment are limited, however. Transplanting a functional parathyroid gland (PTG) would yield better results. Parathyroid gland cells generated from pluripotent stem cells in vitro to date cannot mimic the physiological responses to extracellular calcium that are essential for calcium homeostasis. We thus hypothesized that blastocyst complementation (BC) could be a better strategy for generating functional PTG cells and compensating loss of parathyroid function. We here describe generation of fully functional PTGs from mouse embryonic stem cells (mESCs) with single-step BC. Using CRISPR-Cas9 knockout of Glial cells missing2 (Gcm2), we efficiently produced aparathyroid embryos for BC. In these embryos, mESCs differentiated into endocrinologically mature PTGs that rescued Gcm2-/- mice from neonatal death. The mESC-derived PTGs responded to extracellular calcium, restoring calcium homeostasis on transplantation into mice surgically rendered hypoparathyroid. We also successfully generated functional interspecies PTGs in Gcm2-/- rat neonates, an accomplishment with potential for future human PTG therapy using xenogeneic animal BC. Our results demonstrate that BC can produce functional endocrine organs and constitute a concept in treatment of hypoparathyroidism.

Acute effects of empagliflozin on open-loop baroreflex function and urine glucose excretion in Goto-Kakizaki diabetic rats.

Although suppression of sympathetic activity is suggested as one of the underlying mechanisms for the cardioprotective effects afforded by sodium-glucose cotransporter 2 (SGLT2) inhibitors, whether the modulation of glucose handling acutely affects sympathetic regulation of arterial pressure remains to be elucidated. In Goto-Kakizaki diabetic rats, we estimated the open-loop static characteristics of the carotid sinus baroreflex together with urine glucose excretion using repeated 11-min step input sequences. After the completion of the 2nd sequence, an SGLT2 inhibitor empagliflozin (10 mg kg-1) or vehicle solution was administered intravenously (n = 7 rats each). Empagliflozin did not significantly affect the baroreflex neural or peripheral arc, despite significantly increasing urine glucose excretion (from 0.365 ± 0.216 to 8.514 ± 0.864 mg·min-1·kg-1, P < 0.001) in the 7th and 8th sequences. The possible sympathoinhibitory effect of empagliflozin may be an indirect effect associated with chronic improvements in renal energy status and general disease conditions.

Depletion of plasma thymidine results in growth retardation and mitochondrial myopathy in mice overexpressing human thymidine phosphorylase.

Plasma thymidine levels in rodents are higher than in other mammals including humans, possibly due to a different pattern and lower level of thymidine phosphorylase expression. Here, we generated a novel knock-in (KI) mouse line with high systemic expression of human thymidine phosphorylase to investigate this difference in nucleotide metabolism in rodents. The KI mice showed growth retardation around weaning and died by 4 weeks of age with a decrease in plasma thymidine level compared with the litter-control WT mice. These phenotypes were completely or partially rescued by administration of the thymidine phosphorylase inhibitor 5-chloro-6-(2-iminopyrrolidin-1-yl) methyl-2,4(1H,3H)-pyrimidinedione hydrochloride or thymidine, respectively. Interestingly, when thymidine phosphorylase inhibitor administration was discontinued in adult animals, KI mice showed deteriorated grip strength and locomotor activity, decreased bodyweight, and subsequent hind-limb paralysis. Upon histological analyses, we observed axonal degeneration in the spinal cord, muscular atrophy with morphologically abnormal mitochondria in quadriceps, retinal degeneration, and abnormality in the exocrine pancreas. Moreover, we detected mitochondrial DNA depletion in multiple tissues of KI mice. These results indicate that the KI mouse represents a new animal model for mitochondrial diseases and should be applicable for the study of differences in nucleotide metabolism between humans and mice.

Rationale and study design of the GOREISAN for heart failure (GOREISAN-HF) trial: A randomized clinical trial.

BACKGROUND: The decongestion strategy using loop diuretics is essential for improving signs and symptoms of heart failure (HF). However, chronic use of loop diuretics in HF has been linked to worsening renal function and adverse clinical outcomes in a dose-dependent manner. Goreisan, a traditional Japanese herbal medicine, has a long history of use in Japan for regulating body fluid homeostasis and has been recognized as causing less adverse outcomes such as dehydration in contrast to loop diuretics in clinical practice. Therefore, we designed the GOREISAN-HF trial to evaluate the long-term effects of a new decongestion strategy adding Goreisan to usual care in patients with HF and volume overload. METHODS: The GOREISAN-HF trial is an investigator-initiated, multicenter, pragmatic, randomized, comparative effectiveness trial in which we will enroll 2,192 patients hospitalized for HF at 68 hospitals in Japan. All study participants will be randomly assigned to either a decongestion strategy that adds Goreisan at a dose of 7.5 g daily on top of usual care or usual care alone. Investigators have the flexibility to change the existing diuretic regimen in both groups. The primary end point is the improvement rate of cardiac edema at 12-month follow-up, and the co-primary end point is a composite of all-cause death or hospitalization up to the end of the planned follow-up period. Secondary end points include longitudinal changes in patient-reported outcomes, loop diuretics dose, and renal function. CONCLUSIONS: The GOREISAN-HF is the first large-scale randomized pragmatic trial to assess the efficacy and safety of a new congestion control strategy adding Goreisan to usual care in patients with HF and volume overload. REGISTRATION NUMBER: NCT04691700.

Antibody feedback contributes to facilitating the development of Omicron-reactive memory B cells in SARS-CoV-2 mRNA vaccinees.

In contrast to a second dose of the SARS-CoV-2 mRNA vaccine, a third dose elicits potent neutralizing activity against the Omicron variant. To address the underlying mechanism for this differential antibody response, we examined spike receptor-binding domain (RBD)-specific memory B cells in vaccinated individuals. Frequency of Omicron-reactive memory B cells increased ∼9 mo after the second vaccine dose. These memory B cells show an altered distribution of epitopes from pre-second memory B cells, presumably due to an antibody feedback mechanism. This hypothesis was tested using mouse models, showing that an addition or a depletion of RBD-induced serum antibodies results in a concomitant increase or decrease, respectively, of Omicron-reactive germinal center (GC) and memory B cells. Our data suggest that pre-generated antibodies modulate the selection of GC and subsequent memory B cells after the second vaccine dose, accumulating more Omicron-reactive memory B cells over time, which contributes to the generation of Omicron-neutralizing antibodies elicited by the third vaccine dose.

Trends in prognosis after hospitalization for acute heart failure in Kurashiki Central hospital 2015-2018: single-center prospective study.

Recently, we have been working on enhancing the effectiveness of treatment for acute heart failure (HF) through team-based care. This study was designed to assess the benefits of this initiative by quantifying the prognostic impact on HF patients receiving treatment at our hospital. We identified 1977 consecutive HF patients (mean age 78.3 ± 11.9 years) being discharged from our hospital between February 2015 and December 2018, divided them by admission year, and tracked changes over time, with 2015 as a reference. The postdischarge clinical outcome measures were defined as a composite of all-cause death or rehospitalization for HF, all-cause death, and rehospitalization for HF. The risk of a composite of all-cause death or rehospitalization for HF was lower in 2017 (adjusted hazard ratio, 0.72; 95% confidence interval: 0.57 to 0.91; p = 0.005) and 2018 (adjusted hazard ratio, 0.78; 95% confidence interval: 0.61 to 0.99; p = 0.045) than in 2015, and that of all-cause death was lower in 2017 (adjusted hazard ratio, 0.72; 95% confidence interval: 0.53 to 0.98; p = 0.04) and 2018 (adjusted hazard ratio, 0.60; 95% confidence interval: 0.43 to 0.85; p = 0.004) than in 2015, but that of rehospitalization for HF was not significantly different through the study period. The mortality rate decreased at the end of the study period, but the rate of rehospitalization for HF did not. The benefits of team-based care were difficult to evaluate by quantification.

Ivabradine increases the high frequency gain ratio in the vagal heart rate transfer function via an interaction with muscarinic potassium channels.

Muscarinic potassium channels (IK,ACh ) are thought to contribute to the high frequency (HF) dynamic heart rate (HR) response to vagal nerve stimulation (VNS) because they act faster than the pathway mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. However, the interactions between the two pathways have not yet been fully elucidated. We previously demonstrated that HCN channel blockade by ivabradine (IVA) increased the HF gain ratio of the transfer function from VNS to HR. To test the hypothesis that IVA increases the HF gain ratio via an interaction with IK,ACh , we examined the dynamic HR response to VNS under conditions of control (CNT), IK,ACh blockade by tertiapin-Q (TQ, 50 nM/kg), and TQ plus IVA (2 mg/kg) (TQ + IVA) in anesthetized rats (n = 8). In each condition, the right vagal nerve was stimulated for 10 min with binary white noise signals between 0-10, 0-20, and 0-40 Hz. On multiple regression analysis, the HF gain ratio positively correlated with the VNS rate with a coefficient of 1.691 ± 0.151 (×0.01) (p < 0.001). TQ had a negative effect on the HF gain ratio with a coefficient of -1.170 ± 0.214 (×0.01) (p < 0.001). IVA did not significantly increase the HF gain ratio in the presence of TQ. The HF gain ratio remained low under the TQ + IVA condition compared to controls. These results affirm that the IVA-induced increase in the HF gain ratio is dependent on the untethering of the hyperpolarizing effect of IK,ACh .

Genome editing of Nf1, Pten, and Trp53 in neonatal mice induces glioblastomas positive for oligodendrocyte lineage transcription factor 2.

To generate a mouse glioblastoma model by genome editing, we introduced Cas9 protein and guide RNAs specific for Nf1, Pten, and Trp53 into the neonatal mouse forebrain by electroporation. We found a high incidence (approximately 90%) of glial tumor development, including glioblastomas, 15 weeks later. The histological features of the tumors were similar to those of diffuse gliomas and, in some cases, similar to human glioblastomas, with microvascular proliferation (glomeruloid structure). In addition, unlike glial fibrillary acidic protein (GFAP)-positive glioblastomas generated using a similar method in a previous model, the majority of tumor cells were positive for oligodendrocyte lineage transcription factor 2, but negative for GFAP and neurofilaments. One base pair insertions identical to those seen in a previous model were found around the target sequences in Nf1, Pten, and Trp53, and additional deletions were found only in Pten. Considering that the histological characteristics were different from those seen in the previous model, our new model provides an additional research tool to investigate the early stages of glioblastoma development.

Glycan engineering of the SARS-CoV-2 receptor-binding domain elicits cross-neutralizing antibodies for SARS-related viruses.

Broadly protective vaccines against SARS-related coronaviruses that may cause future outbreaks are urgently needed. The SARS-CoV-2 spike receptor-binding domain (RBD) comprises two regions, the core-RBD and the receptor-binding motif (RBM); the former is structurally conserved between SARS-CoV-2 and SARS-CoV. Here, in order to elicit humoral responses to the more conserved core-RBD, we introduced N-linked glycans onto RBM surfaces of the SARS-CoV-2 RBD and used them as immunogens in a mouse model. We found that glycan addition elicited higher proportions of the core-RBD-specific germinal center (GC) B cells and antibody responses, thereby manifesting significant neutralizing activity for SARS-CoV, SARS-CoV-2, and the bat WIV1-CoV. These results have implications for the design of SARS-like virus vaccines.

A novel method to demonstrate thrombus formation of the left atrial appendage in patients with persistent atrial fibrillation by cardiac computed tomography.

BACKGROUND: Transesophageal echocardiography (TEE) is currently the gold standard technique for diagnosing left atrial appendage (LAA) thrombi. Cardiac computed tomography (CT) has been expected to become an alternative method to TEE; however, a reliable quantitative evaluation method has not been established. METHODS AND RESULTS: We enrolled 177 patients with persistent atrial fibrillation who underwent both cardiac CT and TEE before catheter ablation. The patients were classified into two groups according to the TEE results: the thrombus group (13 patients) and non-thrombus group (164 patients). The Hounsfield unit (HU) density at the proximal LAA (LAAp) and distal LAA (LAAd) was measured on cardiac CT images. The LAAd/LAAp HU ratio and standard deviation of HU density (HU-SD) at the LAAd were evaluated. We created an algorithm by decision tree analysis to predict LAA thrombus formation using the HU ratio and HU-SD. Definite absence of LAA thrombus (Category-I) was diagnosed for 139 patients by combining the first and second branching of the decision tree (Category-Ia: HU ratio of ≥0.26, Category-Ib: HU ratio of <0.26, HD-SD of ≥26.94). Definite presence of LAA thrombus (Category-Ⅱ) was diagnosed for 3 patients using the third branching of the decision tree (Category-Ⅱ: HU ratio of <0.26 and HU-SD of <13.85). Highly possibility of LAA thrombus (Category-III), but not definite, was diagnosed for the remaining 35 patients; therefore, these patients required diagnostic TEE. The diagnostic accuracy of this algorithm was 0.95. CONCLUSION: We have proposed a reliable algorithm to diagnose LAA thrombus formation using the HU ratio and HU-SD.

Open-loop analysis on sympathetically mediated arterial pressure and urine output responses in spontaneously hypertensive rats: effect of renal denervation.

Primary acute sympathetic activation (PASA) causes a subsequent arterial pressure (AP) elevation. In this case, an antidiuretic effect via the renal innervation and pressure diuresis can act antagonistically on the kidneys. We examined the effect of PASA on urine output in spontaneously hypertensive rats (SHR) 4-7 days after unilateral renal denervation (RDN) (n = 9). The slope of the plot of urine flow versus AP was positive (0.120 ± 0.031 µL min-1 kg-1 mmHg-1) on the intact side, but it was less than 1/3 of the slope observed previously in normotensive Wistar-Kyoto rats (WKY). RDN did not normalize the slope of urine flow versus AP (0.179 ± 0.025 µL min-1 kg-1 mmHg-1, P = 0.098 versus the intact side). The urine flow at the operating point of the AP tended to be greater on the denervated than the intact side (29.0 ± 1.8 vs. 25.3 ± 1.9 µL min-1 kg-1, P = 0.055). The percent increase (17.2 ± 7.2%) was not different from that observed previously in WKY. Although high-resting sympathetic nerve activity is prerequisite for maintaining hypertension in SHR, the effect of sympathetic innervation on the urine output function was not greater than that in WKY.

Ivabradine augments high-frequency dynamic gain of the heart rate response to low- and moderate-intensity vagal nerve stimulation under ß-blockade.

Our previous study indicated that intravenously administered ivabradine (IVA) augmented the dynamic heart rate (HR) response to moderate-intensity vagal nerve stimulation (VNS). Considering an accentuated antagonism, the results were somewhat paradoxical; i.e., the accentuated antagonism indicates that an activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels via the accumulation of intracellular cyclic adenosine monophosphate (cAMP) augments the HR response to VNS, whereas the inhibition of HCN channels by IVA also augmented the HR response to VNS. To remove the possible influence from the accentuated antagonism, we examined the effects of IVA on the dynamic vagal control of HR under ß-blockade. In anesthetized rats (n = 7), the right vagal nerve was stimulated for 10 min according to binary white noise signals between 0 and 10 Hz (V0-10), between 0 and 20 Hz (V0-20), and between 0 and 40 Hz (V0-40). The transfer function from VNS to HR was estimated. Under ß-blockade (propranolol, 2 mg/kg iv), IVA (2 mg/kg iv) did not augment the asymptotic low-frequency gain but increased the asymptotic high-frequency gain in V0-10 (0.53 ± 0.10 vs. 1.74 ± 0.40 beats/min/Hz, P < 0.01) and V0-20 (0.79 ± 0.14 vs. 2.06 ± 0.47 beats/min/Hz, P < 0.001). These changes, which were observed under a minimal influence from sympathetic background tone, may reflect an increased contribution of the acetylcholine-sensitive potassium channel (IK,ACh) pathway after IVA, because the HR control via the IK,ACh pathway is faster and acts in the frequency range higher than the cAMP-mediated pathway.NEW & NOTEWORTHY Since ivabradine (IVA) inhibits hyperpolarization-activated cyclic nucleotide-gated channels, interactions among the sympathetic effect, vagal effect, and IVA can occur in the control of heart rate (HR). To remove the sympathetic effect, we estimated the transfer function from vagal nerve stimulation to HR under ß-blockade in anesthetized rats. IVA augmented the high-frequency dynamic gain during low- and moderate-intensity vagal nerve stimulation. Untethering the hyperpolarizing effect of acetylcholine-sensitive potassium channels after IVA may be a possible underlying mechanism.

Characteristics of patients who developed glucose intolerance in the early period after partial pancreatectomy.

BACKGROUND: New-onset diabetes mellitus (DM) often develops after partial pancreatectomy. Little is known regarding how soon patients develop glucose intolerance after partial pancreatectomy. We investigated the incidence of and factors contributing to the development of glucose intolerance during hospitalization after partial pancreatectomy. PATIENTS AND METHODS: We retrospectively analyzed the cases of 38 patients with normal glucose tolerance pre-surgery who underwent a partial pancreatectomy (pancreaticoduodenectomy, n = 23; distal pancreatectomy, n = 15). The patients' glucose tolerance and insulin secretory/sensitivity values were determined by a normal meal tolerance test (NMTT) within 2 months post-surgery during their hospitalization. RESULTS: The post-surgery NMTT values revealed that 11 (28.9%) patients developed new-onset impaired glucose tolerance (the IGT group); the other 27 (71.1%) patients maintained normal glucose tolerance (the NGT group). The pre-operative hemoglobin A1c (HbA1c) levels were significantly higher in the IGT group (5.84%) versus the NGT group (5.58%, p = 0.034). There were no significant between-group differences in age, sex ratio, body mass index, the ratio of operative procedure (either pancreaticoduodenectomy or distal pancreatectomy), or post-operative insulin secretory values including the fasting/postprandial C-peptide index. The IGT group showed significantly higher insulin resistance assessed by the homeostasis model assessment of insulin resistance (HOMA-IR) versus the NGT group (1.52 ± 0.67 vs. 0.65 ± 0.42, p < 0.001). CONCLUSION: After undergoing a partial pancreatectomy, approximately 30% of the patients developed glucose intolerance during the hospitalized period. Our findings indicate that pre-operative HbA1c and post-operative HOMA-IR values can be associated with developing glucose intolerance just after partial pancreatectomy.

Acupoint dependence of depressor and bradycardic responses elicited by manual acupuncture stimulation in humans.

The cardiovascular effects of the autonomic nervous system (ANS) are modulated by inputs from peripheral sensors and other brain regions. However, it currently remains unknown whether the manual acupuncture (MA) stimulation of different acupuncture points evokes different responses by the heart and vasculature, a phenomenon known as "site specificity". Sixty healthy subjects were randomly divided into a control group and MA stimulation groups at the lower leg, ear, abdomen, and forearm. MA was performed at 1 Hz for 2 min. A depressor response was observed only in the lower leg stimulation group, in which mean blood pressure significantly decreased from 83.4 ± 10.1 to 80.9 ± 11.7 mmHg (p < 0.003). A bradycardic response was elicited in all MA stimulation groups. There was no significant differences in the magnitude of the bradycardic response between groups. MA-induced cardiovascular responses, which may be mediated by the modulation of ANS, differ depending on acupuncture points.

Contrasting open-loop dynamic characteristics of sympathetic and vagal systems during baroreflex-mediated heart rate control in rats.

Although heart rate (HR) is governed by the sympathetic and parasympathetic nervous systems, a head-to-head comparison of the open-loop dynamic characteristics of the total arc from a baroreceptor pressure input to the HR response has yet to be performed. We estimated the transfer function from carotid sinus pressure input to the HR response (HCSP→HR) before and after bilateral vagotomy (n = 7) as well as before and after the administration of a ß-blocker propranolol (n = 8) in anesthetized male Wistar-Kyoto rats. The carotid sinus pressure was perturbed according to a Gaussian white noise signal so that the input power spectra were relatively flat between 0.01 and 1 Hz. The gain plot of HCSP→HR was V-shaped. Vagotomy reduced the dynamic gain at 1 Hz (0.0598 ± 0.0065 to 0.0025 ± 0.0004 beats·min-1·mmHg-1, P < 0.001) but not at 0.01 or 0.1 Hz. ß-Blockade reduced the dynamic gain at 0.01 Hz (0.247 ± 0.069 to 0.077 ± 0.017 beats·min-1·mmHg-1, P = 0.020) but not at 0.1 or 1 Hz. We also estimated the efferent limb transfer function from electrical vagal efferent stimulation to the HR response (HVN→HR) under ß-blockade conditions. We associated the model parameters of HVN→HR with the mean HR and the standard deviation of HR so that HVN→HR could be estimated based only on the HR data. We finally estimated the neural arc transfer function from a pressure input to efferent vagal nerve activity by dividing HCSP→HR by HVN→HR. The mathematically determined vagal neural arc showed derivative characteristics with its phase near zero radians at the lowest frequency.

Intravenous ivabradine augments the dynamic heart rate response to moderate vagal nerve stimulation in anesthetized rats.

Ivabradine is a selective bradycardic agent that reduces the heart rate (HR) by inhibiting the hyperpolarization-activated cyclic nucleotide-gated channels. Although its cardiovascular effect is thought to be minimal except for inducing bradycardia, ivabradine could interact with cardiovascular regulation by the autonomic nervous system. We tested whether ivabradine modifies dynamic characteristics of peripheral vagal HR control. In anesthetized Wistar-Kyoto rats (n = 7), the right vagal nerve was sectioned and stimulated for 10 min according to a binary white noise sequence with a switching interval of 500 ms. The efferent vagal nerve stimulation (VNS) trials were performed using three different rates (10, 20, and 40 Hz), and were designated as V0-10, V0-20, and V0-40, respectively. The transfer function from the VNS to the HR was estimated before and after the intravenous administration of ivabradine (2 mg/kg). Ivabradine increased the asymptotic dynamic gain in V0-20 [from 3.88 (1.78-5.79) to 6.62 (3.12-8.31) beats·min-1·Hz-1, P < 0.01, median (range)] but not in V0-10 or V0-40. Ivabradine increased the corner frequency in V0-10 [from 0.032 (0.026-0.041) to 0.064 (0.029-0.090) Hz, P < 0.01] and V0-20 [from 0.040 (0.037-0.056) to 0.068 (0.051-0.100) Hz, P < 0.01] but not in V0-40. In conclusion, ivabradine augmented the dynamic HR response to moderate VNS. At high VNS, however, ivabradine did not significantly augment the dynamic HR response, possibly because ivabradine reduced the baseline HR and limited the range for the bradycardic response to high VNS.NEW & NOTEWORTHY Ivabradine is considered to be a pure bradycardic agent that has little effect on cardiovascular function except inducing bradycardia. The present study demonstrated that ivabradine interacts with the dynamic vagal heart rate control in a manner that augments the heart rate response to moderate-intensity efferent vagal nerve stimulation.

Isolation, Characterisation and Complete Genome Sequence of a Tequatrovirus Phage, Escherichia phage KIT03, Which Simultaneously Infects Escherichia coli O157:H7 and Salmonella enterica.

Escherichia coli O157:H7 and Salmonella enterica subsp. enterica are the pathogens that frequently cause foodborne illness. Bacteriophage applications have been proposed as effective for preventing food contamination caused by these pathogenic bacteria. Escherichia phage KIT03 was isolated from the soil of a poultry farm in Kyoto, Japan. KIT03 can infect Escherichia coli O157:H7 and Salmonella enterica serotypes Choleraesuis and Enteritidis. One-step growth analysis revealed that KIT03 can propagate within its initial host (E. coli NBRC 3972), E. coli O157:H7 and S. Choleraesuis with an approximate burst size of 39, 51 and 37 phage particles per infected cell, respectively. The morphological type and genome annotation suggested that KIT03 belongs to the family Myoviridae, subfamily Tevenvirinae, genus Tequatrovirus. In vitro challenge tests demonstrated that KIT03 can lyse the tested bacteria and suppress their growth. Based on the susceptibility test and adsorption assay of KIT03 with E. coli K-12 BW25113 mutants, it was proposed that KIT03 may recognise and infect bacteria with a deficient outer core of lipopolysaccharides.

Acute effects of intravenous carvedilol versus metoprolol on baroreflex-mediated sympathetic circulatory regulation in rats.

AIMS: To compare the effects of metoprolol and carvedilol on baroreflex-mediated sympathetic circulatory regulation. METHODS: In anesthetized Wistar-Kyoto rats, carotid sinus baroreceptor regions were isolated. Changes in sympathetic nerve activity (SNA), arterial pressure (AP), heart rate (HR), and aortic flow (AoF) in response to a staircase-wise pressure input were examined before (control) and after intravenous injection of low-dose metoprolol (2 mg/kg), high-dose metoprolol (10 mg/kg), or carvedilol (0.67 mg/kg) (n = 6 each). Peripheral vascular resistance (PVR) was calculated from mean AP divided by mean AoF. RESULTS: Low-dose metoprolol had limited effect on sympathetic AP regulation compared to control [operating-point AP (drug vs. control): 88.7 ±â€¯7.1 vs. 98.3 ±â€¯3.3 mm Hg, not significant] despite a significant bradycardic effect. Although high-dose metoprolol showed central sympathoinhibition, it increased PVR at a given SNA as a peripheral effect. Consequently, high-dose metoprolol decreased the operating-point AP slightly (96.1 ±â€¯2.7 vs. 101.9 ±â€¯2.7 mm Hg, P < 0.01). Carvedilol showed no significant central sympathoinhibition at the dose examined in this study, but significantly reduced PVR at a given SNA, leading to a marked reduction in the operating-point AP (71.9 ±â€¯8.2 vs. 112.6 ±â€¯7.6 mm Hg, P < 0.05). CONCLUSION: Low-dose metoprolol has limited hypotensive effect despite blockade of sympathetic HR regulation. Although high-dose metoprolol induces central sympathoinhibition, it also induces peripheral vasoconstriction that antagonizes the hypotensive effect. In contrast, carvedilol exhibits hypotensive effect mainly through peripheral vasodilation. Although carvedilol is frequently classified as a ß-blocker, its vasodilatory effect via α1-adrenergic blockade plays an important role in AP reduction or heart failure treatment.