Molecular Approaches for the Validation of the Baboon as a Nonhuman Primate Model for the Study of Zika Virus Infection

Nonhuman primates (NHP) are particularly important for modeling infections with viruses that do not naturally replicate in rodent cells. Zika virus (ZIKV) has been responsible for sporadic epidemics, but in 2015 a disseminated outbreak of ZIKV resulted in the World Health Organization declaring it a global health emergency. Since the advent of this last epidemic, several NHP species, including the baboon, have been utilized for modeling and understanding the complications of ZIKV infection in humans; several health issues related to the outcome of infection have not been resolved yet and require further investigation. This study was designed to validate, in baboons, the molecular signatures that have previously been identified in ZIKV-infected humans and macaque models. We performed a comprehensive molecular analysis of baboons during acute ZIKV infection, including flow cytometry, cytokine, immunological, and transcriptomic analyses. We show here that, similar to most human cases, ZIKV infection of male baboons tends to be subclinical, but is associated with a rapid and transient antiviral interferon-based response signature that induces a detectable humoral and cell-mediated immune response. This immunity against the virus protects animals from challenge with a divergent ZIKV strain, as evidenced by undetectable viremia but clear anamnestic responses. These results provide additional support for the use of baboons as an alternative animal model to macaques and validate omic techniques that could help identify the molecular basis of complications associated with ZIKV infections in humans.

Early and chronic phased local coagulative responses following bioresorbable-polymer drug-eluting stent implantation

Background

Neointimal maturation after bioresorbable-polymer (BP) drug-eluting stent (DES) implantation will not be complete in the absorption phase of the polymer. We have previously reported local persistent hypercoagulation after sirolimus-eluting stent (SES) implantation by measuring local plasma prothrombin fragment 1+2 (F1+2) levels. The aim of this study is to examine time-dependent local coagulative response after BP-DES implantation.

Methods

Sixty-four patients who were treated about ten months earlier with coronary angioplasty, with no evidence of restenosis, were studied [durable-polymer (DP)-DES {SES; Cypher®: 26pts and everolimus-eluting stent (EES); Xience®: 16pts} and BP-DES (BP-EES; Synergy®: 10pts and BP-SES; Ultimaster®: 12pts)]. We measured plasma levels of F1+2 sampled in coronary sinus (CS) and sinus of Valsalva (V) at the early (2±1 months) and chronic (10±2 months) phases. The transcardiac gradient (Δ) was defined as CS level minus V level.

Results

No significant differences were observed in the percent diameter stenosis between the DP- and BP- DES groups (11.5±15.5 vs 14.1±11.9%). The ΔF1+2 was significantly lower in the BP-DES group than in the DP-DES group at the chronic phase (7.5±16.1 vs 16.4±17.1pmol/l, p<0.05). In the BP-DES group, the ΔF1+2 did not differ significantly between the early and chronic phases (7.0±14.1 vs 7.5±16.1pmol/l, NS).

Conclusion

Lower local coagulative response was observed at the chronic phase after BP-DES implantation compared to DP-DES implantation, and local hypercoagulation after BP-DES implantation was not observed at the early phase compared to the chronic phase. These findings might lead to the possibility of shorter dual antiplatelet therapy after BP-DES implantation.

Funding Acknowledgement

Type of funding sources: None.

Delayed positive COVID19 nasopharyngeal test, a case study with clinical and pathological correlation

Background

There are various reasons for delayed positive nasopharyngeal PCR tests for coronavirus disease 2019 (COVID19) in not only asymptomatic but also severely diseased patients. The pathophysiological attributes are not known. We explore this possibility through a case report.

Case presentation

A 64-year-old male with history of pulmonary fungal infection, asthma and chronic pulmonary obstructive disease (COPD), diabetes, coronary artery disease presented with shortness of breath, fever and chest image of ground opacity, reticular interstitial thickening, highly suspicious for COVID19. However, nasopharyngeal swab tests were discordantly negative for four times in two weeks, and IgG antibody for COVID19 was also negative. However, serum IgE level was elevated. No other pathogens are identified. His symptoms deteriorated despite corticosteroid, antibiotics and bronchodilator treatment. Bronchoalveolar lavage (BAL) and open lung wedge biopsy were performed for etiology diagnosis. They demonstrated COVID19 viral RNA positive fibrosing organizing pneumonia with respiratory tract damage characterized by suspicious viral cytopathic effect, mixed neutrophilic, lymphoplasmacytic, histiocytic and eosinophilic inflammation and fibrosis besides expected asthma and COPD change. One week later, repeated COVID19 nasopharyngeal tests on day 40 and day 49 became positive.

Conclusion

Our case and literature review indicate that allergic asthma and associated high IgE level together with corticosteroid inhalation might contribute to the delayed positive nasopharyngeal swab in upper airway; COPD related chronic airways obstruction and the addition of fibrosis induced ventilator dependence and poor prognosis in COVID19 pneumonia, and should be therapeutically targeted besides antiviral therapy.

Toll-like receptor 9 is a novel therapeutic target to prevent atrial fibrillation

Background

Atrial fibrillation (AF) is the most common type of arrhythmia seen in clinical practice. Recent studies suggest that inflammation contributes to the pathogenesis of AF. On the other hand, several evidence suggests that toll-like receptor (TLR) 9 recognizes bacterial DNA, activating innate immunity, whereas it also provokes inflammation in response to fragmented DNA released from mammalian cells. Recently, we have reported that TLR 9 plays a pivotal role in the development of vascular inflammation and atherogenesis through proinflammatory activation of macrophages.

Purpose

This study aimed to assess whether TLR9 contributes to the AF arrhythmogenesis.

Methods

TLR9 deficient (TLR9−/−) and wild-type mice were infused with angiotensin II (Ang II) or vehicle via an osmotic minipump for 4 weeks. Blood pressure and body weight were measured serially. Then, we examined AF inducibility by intracardiac electrophysiological study and the inflammation-induced atrial remodeling by biochemical analysis after 4 weeks of Ang II infusion.

Results

There was no significant difference in blood pressure and pulse rate between TLR9−/− and wild-type mice both before and after Ang II infusion. Ang II-treated TLR9−/− mice showed lower incidence of AF compared with wild-type mice treated with Ang II. Genetic deletion of TLR9 significantly reduced the interstitial fibrosis in atrium of Ang II-treated mice. TLR9−/− mice also showed less mRNA expressions of inflammatory and fibrosis-related biomarkers (TNF-α, interleukin-6, TGF-β, collagen-1, collagen-3) in atrium compared with wild-type mice.

Conclusions

TLR9 might contribute to the AF arrhythmogenesis associated with atrial inflammation. TLR9 might serve as a potential therapeutic target for AF.

Funding Acknowledgement

Type of funding source: None

Swelling of Doubly Magic ^{48}Ca Core in Ca Isotopes beyond N=28

Interaction cross sections for ^{42-51}Ca on a carbon target at 280  MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

Author Correction: Metagenomic sequencing with spiked primer enrichment for viral diagnostics and genomic surveillance

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Metagenomic sequencing with spiked primer enrichment for viral diagnostics and genomic surveillance

Metagenomic next-generation sequencing (mNGS), the shotgun sequencing of RNA and DNA from clinical samples, has proved useful for broad-spectrum pathogen detection and the genomic surveillance of viral outbreaks. An additional target enrichment step is generally needed for high-sensitivity pathogen identification in low-titre infections, yet available methods using PCR or capture probes can be limited by high cost, narrow scope of detection, lengthy protocols and/or cross-contamination. Here, we developed metagenomic sequencing with spiked primer enrichment (MSSPE), a method for enriching targeted RNA viral sequences while simultaneously retaining metagenomic sensitivity for other pathogens. We evaluated MSSPE for 14 different viruses, yielding a median tenfold enrichment and mean 47% (±16%) increase in the breadth of genome coverage over mNGS alone. Virus detection using MSSPE arboviral or haemorrhagic fever viral panels was comparable in sensitivity to specific PCR, demonstrating 95% accuracy for the detection of Zika, Ebola, dengue, chikungunya and yellow fever viruses in plasma samples from infected patients. Notably, sequences from re-emerging and/or co-infecting viruses that have not been specifically targeted a priori, including Powassan and Usutu, were successfully enriched using MSSPE. MSSPE is simple, low cost, fast and deployable on either benchtop or portable nanopore sequencers, making this method directly applicable for diagnostic laboratory and field use.

This study describes a new method that improves the sensitivity of viral detection compared with next-generation sequencing and enables the detection of emerging flaviviruses not specifically targeted a priori. Metagenomic sequencing with spiked primer enrichment is simple, low cost, fast and deployable on either benchtop or portable nanopore sequencers, making it applicable for diagnostic laboratory and field use.

P2813The improvement of chronic local coagulative response according to the progress of drug eluting stent

Background

We have previously reported local persistent hypercoagulation after sirolimus-eluting stent (SES) implantation by measuring local plasma prothrombin fragment 1+2 (F1+2) levels. The aim of this study is to examine chronic local coagulative response after each generation- drug eluting stent (DES) implantation.

Methods

Ninety-five patients who were treated about eight months earlier with coronary angioplasty, with no evidence of restenosis, were studied [1stgeneration durable polymer (DP)-DES {SES; Cypher®: 26pts, paclitaxel-eluting stent (PES); Taxus®:16pts}, 2ndgeneration DP-DES {everolimus-eluting stent (EES); Xience®:15pts, zotarolimus-eluting stent (ZES); Endeavor®:15pts}, and 3rdgeneration biodegradable polymer (BP)-DES {BP-biolimus-eluting stent (BES); Nobori®: 11pts and BP-SES; Ultimaster®: 12pts}]. We measured plasma levels of F1+2 sampled in coronary sinus (CS) and sinus of Valsalva (V). The transcardiac gradient (Δ) was defined as CS level minus V level.

Results

No significant differences were observed in the percent diameter stenosis among 1st, 2nd, and 3rd DES groups (12.5±15.5 vs 16.1±12.9 vs 13.1±11.9%). The ΔF1+2 was significantly lower in the 2nd and 3rd DES groups than in the 1st DES group (9.0±15.4 and 10.0±17.4 vs 27.3±23.8pmol/l, p<0.05, respectively). The ΔF1+2 was significantly lower in the BP-DES groups (BP-BES and BP-SES) than in the DP-DES groups (DP-SES, DP-PES, DP-ZES, and DP-EES) (10.0±17.4 vs 18.1±19.5pmol/l, p<0.05). The ΔF1+2 was significantly lower in the thin strut-DES groups (BP-SES, DP-ZES, and DP-EES) than in the thick strut-DES groups (DP-SES, DP-PES, and BP-BES) (8.4±15.4 vs 21.7±18.5pmol/l, p<0.05). In the BP-DES groups, the ΔF1+2 was lower in the BP-SES group than in the BP-BES group (8.0±16.1 vs 12.7±18.1pmol/l, p=0.08).

Conclusions

The improvement of chronic local coagulative response was observed according to the progress of DES. These findings might be associated with lower strut thickness and faster polymer resorption in the newer-generation DES.

P3437Impact of epicardial adipose tissue on global longitudinal strain: a study in patients with normal left ventricular ejection fraction

Background

Epicardial adipose tissue (EAT) locates anatomically and functionally contiguous to the myocardium and coronary arteries. It has been suggested that EAT accumulation is associated with cardiac remodeling and impaired cardiac performance. However, its role in left ventricular (LV) wall strain remains unclear.

Purpose

In this study, we aimed to clarify: whether EAT accumulation is related to global longitudinal (GLS), circumferential (CS) and radial strain (RS); and if so, in which extent or by which amount of EAT are required to deteriorate these strain.

Methods

Total 180 patients who had no obstructive coronary artery disease (CAD) on multi-detector computed tomography (MDCT) coronary angiography and normal left ventricular ejection fraction (LVEF) on conventional echocardiography were recruited. Cardiac CT was used to quantify EAT volume (EATV) and echocardiographic speckle tracking was used to measure the GLS, CS and RS. EATV index (EATV/Body surface area) was determined as: EAT volume, the sum of the EAT area from the base to the apex of the heart (cm3)/body surface area (m2). Adipose tissue was determined as the density range between −190 and −30 Hounsfield unit. According to the median value (68 cm3/m2), patients were divided into lower and higher EATV index two groups.

Results

In higher EATV index group (95±19 cm3/m2), mean age, body mass index (BMI), prevalence of hyperlipidemia and prevalence of CAD were larger than in lower EATV index group (48±14 cm3/m2). Male gender, hypertension, diabetes, smoking and LV mass index were comparable between two groups. Patients in higher EATV index had lower GLS than those in lower EATV index (−19.4±1.2% vs. −18.8±1.3%, p=0.002). However, there were no significant difference between two groups regarding to the CS and RS. Linear regression analysis showed that there was strong correlation between EATV index and GLS (R=0.216, p=0.004); whereas, both RS and CS were strongly associated with the interventricular septum thickness (RS: R=0.248, p=0.003; CS: R= −0.192, p=0.023) and relative wall thickness (RS: R=0.178, p=0.036; CS: R= −0.184, p=0.030) but not with EATV; on multiple regression analysis, EATV was a predictor of GLS independent of age, male gender, BMI, diabetes, hyperlipidemia, hypertension and CAD (Adjusted R2=0.238, p<0.001).

Conclusion

EATV is independently associated with GLS despite the preserved LVEF and lacking of obstructive CAD, and may play a significant role in estimating impaired longitudinal LV performance.

P2867Vildagliptin reduces inducibility of atrial fibrillation in hypertensive rats complicated with diabetes mellitus

Background

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice, increasing the incidence of ischemic stroke. Diabetes mellitus (DM) is a predictor of stroke and thromboembolism, and it was reported to be an independent risk factor for AF. A recent study has shown that, in obese mice with diabetes, dipeptidyl peptidase-4 (DPP-4) inhibitor prevents myocardial fibrosis, active oxygen stress, weight loss and improves myocardial hypertrophy. However, the effects of DPP-4 inhibitors on atrial remodeling associated with diabetes and atrial fibrillation have not yet been clarified.

Purpose

This study was performed to assess whether a DPP-4 inhibitor (vildagliptin) ameliorates atrial remodeling in spontaneously hypertensive rats (SHR) with streptozotocin-induced diabetes.

Methods

Rats were divided into 3 groups: SHR without DM, SHR with DM treated with vehicle and SHR-DM treated with vildagliptin (3mg/kg/day; intragastric gavage). For each group, blood pressure, blood glucose level and body weight were measured serially. Cardiac function was also evaluated by echocardiography. Then, we examined AF inducibility by intracardiac electrophysiological study and the inflammation-induced atrial remodeling by biochemical analysis after 4 weeks of treatment.

Results

There was no significant difference in blood pressure and blood gucose level between vehicle and vildagliptin groups. Administration of vildagliptin significantly reduced AF inducibility compared with rats with vehicle. In DM rats treated with vehicle, rapid atrial pacing promoted the gene expression of inflammatory and fibrosis-related biomarkers (TNF-α, MCP-1, collagen-1) in atrium. Vildagliptin reduced these gene expression levels. In addition, administration of vildagliptin significantly reduced the interstitial fibrosis in atrium.

Conclusions

DPP-4 inhibitor, vildagliptin. could prevent atrial inflammation and reduce the AF inducibility in SHR complicated with DM.

P3111Empagliflozin, a SGLT2 inhibitor, attenuates endothelial dysfunction and atherogenesis by inhibiting inflammatory responses in the vasculature and adipose tissue in diabetic apolipoprotein E-deficient

Background

Inflammation and oxidative stress associated with hyperglycemia are major causes of vascular dysfunction and cardiovascular complications in diabetes. Recent studies reported that cardioprotective effects of sodium glucose co-transporter 2 (SGLT2) inhibitors, however underlying mechanisms are still obscure.

Purpose

The aim of this study was to investigate whether empagliflozin attenuates atherogenesis and endothelial dysfunction in diabetic apolipoprotein E-deficient (ApoE−/−) mice and investigated underlying mechanisms.

Methods

ApoE−/− mice were injected with streptozotocin (75 mg/kg) for 3 consecutive days. One week after last injection, a western type diet and administration of empagliflozin (20 mg/kg/day) or vehicle via oral gavage were started. Atherosclerotic plaque area was examined by en face Sudan IV staining. Lipid deposition and inflammatory features of atherosclerotic plaques was examined on lesions in the aortic root by immunohistochemical analysis. Vascular function was assessed by isometric tension recording. mRNA or protein expression level was examined by quantitative RT-PCR (qPCR) or western blot analysis, respectively. In in vitro experiments, murine macrophage cell line, RAW264.7, was used.

Results

Treatment with empagliflozin for 12 weeks significantly decreased atherosclerotic plaque size in the aortic arch compared with untreated group (p<0.01). Empagliflozin reduced blood glucose (p<0.001) and plasma lipid levels. Results of histological analyses revealed that empagliflozin decreased lipid deposition, macrophage accumulation, and the expression of inflammatory molecules in the aortic root. Empagliflozin treatment for 8 weeks significantly attenuated endothelial dysfunction as determined by vascular response to acetylcholine. qPCR results demonstrated that empagliflozin reduced the expression of inflammatory molecules such as MCP-1 (p<0.05), ICAM-1 (p<0.05) and Nox-2 (p<0.05), a major NADPH oxidase subunit, in the aorta compared with the untreated group. Furthermore, empagliflozin significantly mitigated the expression of these inflammatory molecules in fat tissues around the aortic arch as determined by qPCR. In in vitro studies, methylglyoxal (MGO), a precursor of AGEs, increased the expression of inflammatory molecules (e.g., MCP-1, IL-1b and TNF-a (p<0.05, respectively)) in RAW264.7 cells. MGO also significantly induced activation of JNK and p38 MAP kinase (p<0.001, respectively) in this cell-type.

Conclusions

Empagliflozin attenuated endothelial dysfunction and atherogenesis in diabetic ApoE−/− mice. Reduction of inflammation in the vasculature and peri-vascular adipose tissues may have a role as underlying mechanisms at least partially.

3306Endothelial cell senescence accelerates atherosclerosis by enhancing monocyte recruitment via hyper-reactivity to inflammatory stimuli

Background

Ageing is a significant risk factor for atherosclerotic diseases. Vascular senescence has been considered to play an important role in the progression of atherosclerosis; however, it remains unclear whether endothelial cell (EC) senescence is causally involved in the pathogenesis of atherosclerosis.

Purpose

The purpose of this study is to elucidate a causative role of senescent EC in the progression of atherosclerosis.

Methods

Telomeric repeat-binding factor 2 (TRF2) plays a central role in telomere maintenance and protection against end-to-end fusion of chromosome. We previously reported that overexpression of TRF2-dominant negative mutant (TRF2DN) induced premature senescence in EC. We recently generated EC-specific progeroid mice by overexpressing TRF2DN specifically in EC (TRF2DN-Tg), and then generated ApoE-KO/TRF2DN-Tg mice to analyze a role of EC senescence in atherosclerosis. These mice were fed with a high cholesterol-diet, and atherosclerosis was assessed by en face analysis of whole aorta and histological analysis of aortic sinus. In vitro studies to analyze the underlying mechanisms were performed using replicative senescent HUVECs.

Results

En face analysis of aorta revealed that atherosclerotic lesions were significantly increased in ApoE-KO/TRF2DN-Tg mice comparing with that in ApoE-KO mice at as early as 2 weeks after high-cholesterol diet. Histological analysis of aortic sinus also exhibited accelerated atherosclerosis in ApoE-KO/TRF2DN-Tg mice in association with increased macrophage infiltration. Mechanistically, we found that the induction of adhesion molecules such as VCAM-1, ICAM-1, and E-selectin in response to low-grade inflammatory stimuli was substantially augmented in senescent ECs comparing with that in young ECs. As a result, monocyte adhesion was significantly enhanced in senescent ECs. Of note, eNOS inhibition did not affect the hyper-reactivity of senescent EC to inflammation, while antagonizing NF-kB abolished it. Nuclear translocation of NF-kB in response to inflammation was not different between young and senescent ECs, suggesting that NF-kB transcriptional activity might be enhanced in senescent ECs.

Conclusion

We revealed a causative role of EC senescence in the progression of atherosclerosis in vivo using unique EC-specific progeroid mice. Our findings revealed that EC senescence is a bona fide risk for atherosclerosis, and thus senescent ECs are attracting pharmacotherapeutic targets for the prevention and/or treatment of atherosclerotic disease in elderly population.

P5304Adipose tissue surrounding the kidney and its impact on coronary artery disease

Background

Growing evidence suggests that visceral adipose tissue has systemic and local impact for the development of cardiovascular disease. Previously, we reported that epicardial adipose tissue, as one of visceral fat, was a risk factor for the development of coronary artery disease (CAD). However, the association between another visceral adiposity kidney fat and CAD remains unclear.

Purpose

In this study we aimed to clarify whether there exists link between adipose tissue surrounding the kidney and CAD among patients.

Method

The study population consisted of 201 consecutive patients who underwent 320-slice multi-detector computed tomography (MDCT) coronary angiography. Study subjects were divided into the CAD (≥1 coronary artery stenosis of ≥50%) and non-CAD groups. Adipose tissue surrounding the kidney were quantified by the computed tomography and peri-renal fat volumetric measurements were performed on axial views by manually placing the Region of Interest (ROI) on the renal fascia. The peri-renal fat area of each slice was summed and multiplied by the slice thickness and number of slices to determine the total peri-renal fat volume. Adipose tissue was determined as the density range was −190 to −30 Hounsfield unit. Peri-renal fat volume were indexed by body surface area (BSA).

Results

The mean age was higher in CAD group than those in non-CAD (66±11 vs. 71±10 years, p=0.005). The diabetes, hypertension and hyperlipidemia were significantly prevalent in CAD comparing to non-CAD group. BSA adjusted Peri-renal fat volume was significantly larger in CAD than those in non-CAD (43±27 vs. 60±39 ml/m2). Linear regression analysis showed that BSA adjusted peri-renal fat volume was significantly correlated with visceral fat area (VFA) (R=0.729, p<0.001). Multiple regression analysis for estimating CAD showed that BSA adjusted peri-renal fat volume was a predictor of CAD after adjusting for confounding factors which including age, gender, body mass index, smoking, hypertension, hyperlipidemia, diabetes and VFA (Adjusted R2=0.201, p<0.001); In addition, in the above traditional risk factors model even when the VFA was replaced by the eGFR<60 ml/min/1.73m2, the BSA adjusted peri-renal fat volume still keep a significance for predicting the CAD in the multivariate analysis (Adjusted R2=0.198, p<0.001).

Conclusion

Peri-renal fat volume might be a predictor of CAD. Kidney fat at least partially may contributes to the development of CAD by impaired kidney function.

P722Glycemic control with canagliflozin, a SGLT-2 inhibitor, attenuates atherosclerosis and endothelial dysfunction in diabetic apolipoprotein e-deficient mice

Background

Canagliflozin is a SGLT-2 inhibitor, a novel type of drug for type 2 diabetes mellitus treatment. Recent studies have shown that SGLT-2 inhibitors reduce cardiovascular events, although the mechanism is still unknown.

Purpose

The aim of our study was to examine the effect of canagliflozin on vascular endothelial cell.

Method

Eight-week-old apolipoprotein E-deficient (ApoE−/−) mice were treated with streptozotocin (STZ, 75 mg/kg/day) in three consecutive days by intraperitoneal injection to induce diabetes. Diabetic ApoE−/− mice were treated with canagliflozin (30 mg/kg/day) by gavage for 12 weeks or 8 weeks to examine its effect on atherosclerosis or endothelial function, respectively.

Results

Canagliflozin significantly decreased blood glucose level (P<0.001), triglyceride level (P<0.05), and total cholesterol level (P<0.05). Sudan IV staining on the aortic arch showed that canagliflozin decreased atherosclerotic lesion progression (P<0.05). Histological analyses using atherosclerotic lesions in the aortic root showed that canagliflozin reduced lipid disposition (P<0.01), macrophage accumulation (P<0.001, and expression of adhesion molecules such as ICAM-1, and VCAM-1 (P<0.01, and P<0.05 respectively). Canagliflozin also attenuated the development of endothelial dysfunction as determined by acetylcholine-dependent vasodilation (P<0.05), and reduced the expression of inflammatory molecules, such as ICAM-1 and VCAM-1 (P<0.01), also MCP-1, F4/80, IL6, and iNOS (P<0.05) in the aorta. Canagliflozin reduced oxidative stress as determined by the reduction of the expression of NOX2, NOX4, p22phox, p47phox in the aorta and by the urinary excretion of 8-OHdG. In in vitro experiment using human umbilical vein endothelial cells (HUVEC), methylglyoxal (MGO), a precursor of advanced glycation end products, significantly increased the expression of inflammatory molecules such as ICAM-1, MCP-1, and p22phox in (P<0.05, respectively). MGO also decreased the phosphorylation of eNOSser1177 and Akt, and increased phosphorylation of P38 MAPK in HUVEC.

Conclusion

Glucose lowering effect by canagliflozin attenuates the development of endothelial dysfunction and atherogenesis in diabetic ApoE−/− mice. Anti-inflammatory effect due to the reduction of glucose toxicity on endothelial cells might be one of the mechanisms.

Development of Recombinant Methioninase for Cancer Treatment

The elevated requirement for methionine (MET) of cancer cells is termed MET dependence. To selectively target the MET dependence of tumors for treatment on a large-scale preclinical and clinical basis, the L-methionine α-deamino-γ-mercaptomethane-lyase (EC 4.4.1.11) (methioninase, [METase]) gene from Pseudomonas putida has been cloned in Escherichia coli using the polymerase chain reaction (PCR). Purification using two DEAE Sepharose FF ion-exchange column and one ActiClean Etox endotoxin-affinity chromatography column has been established. Plasmid pMGLTrc03, which has a trc promoter and a spacing of 12 nucleotides between the Shine-Dalgarno sequence and the ATG translation initiation codon, was selected as the most suitable plasmid. The recombinant bacteria produced rMETase at 43% of the total proteins in soluble fraction by simple batch fermentation using a 500 L fermentor. Crystals were directly obtained from crude enzyme with 87% yield by a crystallization in the presence of 9.0% polyethylene glycol 6000, 3.6% ammonium sulfate, and 0.18 M sodium chloride using a 100 L crystallizer. After recrystallization, the enzyme was purified by anion-exchange column chromatography to remove endotoxins and by gel filtration for polishing. Purified rMETase is stable to lyophilization. In order to prevent immunological reactions which might be produced by multiple dosing of rMETase and to prolong the serum half-life of rMETase, the N-hydroxysuccinimidyl ester of methoxypolyethylene glycol propionic acid (M-SPA-PEG 5000) has been coupled to rMETase. The PEGylated molecules (PEG-rMETase) were purified from unreacted PEG with Amicon 30 K centriprep concentrators or by Sephacryl S-300 HR gel-filtration chromatography. Unreacted rMETase was removed by DEAE Sepharose FF anion-exchange chromatography. The resulting PEG-rMETase subunit, produced from a PEG/rMETase ratio of 30/1 in the synthetic reaction, had a molecular mass of approximately 53 kda determined by matrix-assisted laser desorption/ionization mass spectrometry, indicating the conjugation of two PEG molecules per subunit of rMETase and eight per tetramer. PEG-rMETase molecules obtained from reacting ratios of PEG/rMETase of 30/1 had an enzyme activity of 70% of unmodified rMETase. PEGylation of rMETase increased the serum half-life of the enzyme in rats to approximately 160 min compared to 80 min for unmodified rMETase. PEG-rMETase could deplete serum MET levels to less than 0.1 μM for approximately 8 h compared to 2 h for rMETase in rats. A significant prolongation of in vivo activity and effective MET depletion by the PEG-rMETase were achieved by the simultaneous administration of pyridoxal 5'-phosphate. rMETase was also conjugated with methoxypolyethylene glycol succinimidyl glutarate 5000 (MEGC-PEG). Miniosmotic pumps containing various concentrations of PLP were implanted in BALB-C mice. PLP-infused mice were then injected with a single dose of 4000 or 8000 units/kg PEG-rMETase. Mice infused with 5, 50, 100, 200, and 500 mg/mL PLP-containing miniosmotic pumps increased plasma PLP to 7, 24, 34, 60, and 95 μM, respectively, from the PLP baseline of 0.3 μM. PLP increased the half-life of MEGC-PEG-rMETase holoenzyme in a dose-dependent manner. The extended time of MET depletion by MEGC-PEG-rMETase was due to the maintenance of active MEGC-PEG-rMETase holoenzyme by infused PLP.

Safety and Toxicity of Recombinant Methioninase and Polyethylene Glycol (PEG) Recombinant Methioninase in Primates

Methionine (MET) is a general metabolic therapeutic target in cancer, whereby cancer cells have an elevated requirement for MET, termed MET dependence. We have developed recombinant L-methionine α-deamino-γ-mercaptomethane lyase (recombinant methioninase [rMETase, EC 4.4.1.11]) as targeted therapy of all cancer types. Pharmacokinetics, MET depletion, antigenicity, and toxicity of rMETase were examined in macaque monkeys. Pharmacokinetic analysis showed that rMETase was eliminated with a T_1/2 of 2.49 h. A 2-week i.v. administration of 4000 units/kg every 8 h/day for 2 weeks resulted in a steady-state depletion of plasma MET to less than 2 μM. The only manifest toxicity was decreased food intake and slight weight loss. Serum albumin and red-cell values declined transiently during treatment. Rechallenge on day 28 resulted in anaphylactic shock and death in one animal. Pretreatment with hydrocortisone prevented the anaphylactic reaction. Anti-rMETase antibodies (at 10^-3) were found after the first challenge, increased to 10^-6 after the fourth challenge, and decreased to 10^-2 by 2 months post-therapy. Therefore, the therapeutic potential of rMETase is limited by its short plasma half-life and immunologic effects, including high antibody production in mice and anaphylactic reactions in monkeys. To overcome these limits, rMETase has been coupled to methoxypolyethylene glycol succinimidyl glutarate polyethylene glycol (MEGC-PEG-5000). The pharmacokinetics, antigenicity, and toxicity of MEGC-PEG-rMETase in macaque monkeys were evaluated using an escalating-dose strategy. In pharmacokinetic studies, a single 4000 units/kg dose showed that MEGC-PEG-rMETase holoenzyme activity was eliminated with a biological half-life of 1.3 h, and the MEGC-PEG-rMETase apoenzyme was eliminated with a biological half-life of 90 h, a 36-fold increase compared with non-PEGylated rMETase. The disparity in the T_½ of the apoenzyme and the holoenzyme reflects the loss of co-factor pyridoxal-L-phosphate of the circulating MEGC-PEG-rMETase. A 7-day i.v. administration of 4000 units/kg every 12 h resulted in a steady-state depletion of plasma MET to <5 μmol/L. The only manifest toxicity was decreased food intake and slight weight loss. Red cell values and hemoglobin declined transiently. Subsequent challenges did not result in any immunologic reactions. Anti-MEGC-PEG-rMETase antibodies were 100- to 1000-fold less than antibodies elicited by naked rMETase, thereby suggesting clinical potential of MEGC-PEG-rMETase as a broad anticancer agent.

Henoch-Schönlein Purpura After Living Donor Liver Transplantation: Report of the First Case

Henoch-Schönlein purpura (HSP) is a systemic vasculitis affecting the small vessels that mainly presents in children and young adults. It is characterized by tissue deposition of immunoglobulin A (IgA) immune complexes with the classic manifestations of purpura, arthritis, arthralgia, and gastrointestinal and renal involvements. We report a case of HSP nephritis that occurred 2 years after living-donor liver transplantation (LDLT). After pulse steroid administration, the patient's symptoms disappeared and blood markers normalized. To the best of our knowledge, this is the first HSP case to be reported in a liver transplant recipient.

Genomic Epidemiology Reconstructs the Introduction and Spread of Zika Virus in Central America and Mexico

The Zika virus (ZIKV) epidemic in the Americas established ZIKV as a major public health threat and uncovered its association with severe diseases, including microcephaly. However, genetic epidemiology in some at-risk regions, particularly Central America and Mexico, remains limited. We report 61 ZIKV genomes from this region, generated using metagenomic sequencing with ZIKV-specific enrichment, and combine phylogenetic, epidemiological, and environmental data to reconstruct ZIKV transmission. These analyses revealed multiple independent ZIKV introductions to Central America and Mexico. One introduction, likely from Brazil via Honduras, led to most infections and the undetected spread of ZIKV through the region from late 2014. Multiple lines of evidence indicate biannual peaks of ZIKV transmission in the region, likely driven by varying local environmental conditions for mosquito vectors and herd immunity. The spatial and temporal heterogeneity of ZIKV transmission in Central America and Mexico challenges arbovirus surveillance and disease control measures.

Experimental Zika Virus Infection in the Pregnant Common Marmoset Induces Spontaneous Fetal Loss and Neurodevelopmental Abnormalities

During its most recent outbreak across the Americas, Zika virus (ZIKV) was surprisingly shown to cause fetal loss and congenital malformations in acutely and chronically infected pregnant women. However, understanding the underlying pathogenesis of ZIKV congenital disease has been hampered by a lack of relevant in vivo experimental models. Here we present a candidate New World monkey model of ZIKV infection in pregnant marmosets that faithfully recapitulates human disease. ZIKV inoculation at the human-equivalent of early gestation caused an asymptomatic seroconversion, induction of type I/II interferon-associated genes and proinflammatory cytokines, and persistent viremia and viruria. Spontaneous pregnancy loss was observed 16-18 days post-infection, with extensive active placental viral replication and fetal neurocellular disorganization similar to that seen in humans. These findings underscore the key role of the placenta as a conduit for fetal infection, and demonstrate the utility of marmosets as a highly relevant model for studying congenital ZIKV disease and pregnancy loss.

Experimental Zika Virus Inoculation in a New World Monkey Model Reproduces Key Features of the Human Infection

A monkey model of Zika virus (ZIKV) infection is urgently needed to better understand transmission and pathogenesis, given its proven association with fetal brain defects in pregnant women and acute neurological illness. Here we experimentally infected 4 male marmosets with ZIKV (prototype 1947 African strain) and monitored them clinically with sampling of various body fluids and tissues for nearly 3 months. We show that the course of acute infection with ZIKV in these New World monkeys resembles the human illness in many respects, including (1) lack of apparent clinical symptoms in most cases, (2) persistence of the virus in body fluids such as semen and saliva for longer periods of time than in serum, and (3) generation of neutralizing antibodies as well as an antiviral immunological host response. Importantly, ZIKV-infected saliva samples (in addition to serum) were found to be infectious, suggesting potential capacity for viral transmission by the oral route. Re-challenge of a previously infected marmoset with a contemporary outbreak strain SPH2015 from Brazil resulted in continued protection against infection, no viral shedding, and boosting of the immune response. Given the key similarities to human infection, a marmoset model of ZIKV infection may be useful for testing of new drugs and vaccines.

Coexistent End-stage Nonalcoholic Steatohepatitis and Colon Cancer: Should We Do Liver Transplantation?

BACKGROUND

Colon cancer accompanying decompensated liver cirrhosis is a rare clinical condition. Usually, treatment of colon cancer is prioritized, with cirrhosis dealt with later.

CASE REPORT

We present a case of end-stage liver disease due to nonalcoholic steatohepatitis evaluated for living donor liver transplant. During the pretransplant examination, an ascending colon cancer was detected. Liver function was too poor to perform colon resection first. Simultaneous living donor liver transplant and colonic resection were carried out. The patient developed left lung metastasis at 2 different times during the first postoperative year, and both of them were resected. The patient received the standard chemoradiotherapy. Now, the patient is alive at 42 months postprocedure and recurrence-free at 31 months postoperatively.

CONCLUSION

Simultaneous liver transplantation and colon resection are possible with acceptable long-term outcomes. Immunosuppressive therapy after transplantation increases the risk for cancer recurrence. So the patient should undergo close surveillance.

A mouse model of paralytic myelitis caused by enterovirus D68

In 2014, the United States experienced an epidemic of acute flaccid myelitis (AFM) cases in children coincident with a nationwide outbreak of enterovirus D68 (EV-D68) respiratory disease. Up to half of the 2014 AFM patients had EV-D68 RNA detected by RT-PCR in their respiratory secretions, although EV-D68 was only detected in cerebrospinal fluid (CSF) from one 2014 AFM patient. Given previously described molecular and epidemiologic associations between EV-D68 and AFM, we sought to develop an animal model by screening seven EV-D68 strains for the ability to induce neurological disease in neonatal mice. We found that four EV-D68 strains from the 2014 outbreak (out of five tested) produced a paralytic disease in mice resembling human AFM. The remaining 2014 strain, as well as 1962 prototype EV-D68 strains Fermon and Rhyne, did not produce, or rarely produced, paralysis in mice. In-depth examination of the paralysis caused by a representative 2014 strain, MO/14-18947, revealed infectious virus, virion particles, and viral genome in the spinal cords of paralyzed mice. Paralysis was elicited in mice following intramuscular, intracerebral, intraperitoneal, and intranasal infection, in descending frequency, and was associated with infection and loss of motor neurons in the anterior horns of spinal cord segments corresponding to paralyzed limbs. Virus isolated from spinal cords of infected mice transmitted disease when injected into naïve mice, fulfilling Koch’s postulates in this model. Finally, we found that EV-D68 immune sera, but not normal mouse sera, protected mice from development of paralysis and death when administered prior to viral challenge. These studies establish an experimental model to study EV-D68-induced myelitis and to better understand disease pathogenesis and develop potential therapies.

Reports of polio-like paralysis, referred to as acute flaccid myelitis (AFM), have recently emerged in association with infections caused by enterovirus D68 (EV-D68). In the second half of 2014, 120 cases of AFM, mostly in young children, were reported during a nationwide outbreak of EV-D68 respiratory disease. The number of AFM cases has risen again in 2016. Although epidemiological evidence between EV-D68 infection and AFM is accumulating, a causal link has not been definitely established. Here we demonstrate that strains of EV-D68 recovered during the 2014 epidemic can cause a paralytic illness in mice that resembles human AFM. Evidence that EV-D68 causes paralysis in this mouse model include: (1) loss of spinal cord motor neurons innervating paralyzed limbs, (2) detection of virus in the spinal cord and, specifically, motor neurons, (3) transmission of neurological disease when injecting virus isolated from spinal cords of paralyzed mice into naïve mice, thus fulfilling Koch’s postulates, and (4) the ability to prevent AFM by pre-administering serum containing EV-D68 antibodies from previously infected mice. This experimental mouse model can be used to better understand the pathogenesis of EV-D68-induced CNS disease and to facilitate the development of potential therapies.

Two-Proton Radioactivity of ^{67}Kr

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.

Acute Flaccid Myelitis of Unknown Etiology in California, 2012-2015

IMPORTANCE

There has been limited surveillance for acute flaccid paralysis in North America since the regional eradication of poliovirus. In 2012, the California Department of Public Health received several reports of acute flaccid paralysis cases of unknown etiology.

OBJECTIVE

To quantify disease incidence and identify potential etiologies of acute flaccid paralysis cases with evidence of spinal motor neuron injury.

DESIGN, SETTING, AND PARTICIPANTS

Case series of acute flaccid paralysis in patients with radiological or neurophysiological findings suggestive of spinal motor neuron involvement reported to the California Department of Public Health with symptom onset between June 2012 and July 2015. Patients meeting diagnostic criteria for other acute flaccid paralysis etiologies were excluded. Cerebrospinal fluid, serum samples, nasopharyngeal swab specimens, and stool specimens were submitted to the state laboratory for infectious agent testing.

MAIN OUTCOMES AND MEASURES

Case incidence and infectious agent association.

RESULTS

Fifty-nine cases were identified. Median age was 9 years (interquartile range [IQR], 4-14 years; 50 of the cases were younger than 21 years). Symptoms that preceded or were concurrent included respiratory or gastrointestinal illness (n = 54), fever (n = 47), and limb myalgia (n = 41). Fifty-six patients had T2 hyperintensity of spinal gray matter on magnetic resonance imaging and 43 patients had cerebrospinal fluid pleocytosis. During the course of the initial hospitalization, 42 patients received intravenous steroids; 43, intravenous immunoglobulin; and 13, plasma exchange; or a combination of these treatments. Among 45 patients with follow-up data, 38 had persistent weakness at a median follow-up of 9 months (IQR, 3-12 months). Two patients, both immunocompromised adults, died within 60 days of symptom onset. Enteroviruses were the most frequently detected pathogen in either nasopharynx swab specimens, stool specimens, serum samples (15 of 45 patients tested). No pathogens were isolated from the cerebrospinal fluid. The incidence of reported cases was significantly higher during a national enterovirus D68 outbreak occurring from August 2014 through January 2015 (0.16 cases per 100,000 person-years) compared with other monitoring periods (0.028 cases per 100,000 person-years; P <.001).

CONCLUSIONS AND RELEVANCE

In this series of patients identified in California from June 2012 through July 2015, clinical manifestations indicated a rare but distinct syndrome of acute flaccid paralysis with evidence of spinal motor neuron involvement. The etiology remains undetermined, most patients were children and young adults, and motor weakness was prolonged.

Clinical metagenomic identification of Balamuthia mandrillaris encephalitis and assembly of the draft genome: the continuing case for reference genome sequencing

Background

Primary amoebic meningoencephalitis (PAM) is a rare, often lethal, cause of encephalitis, for which early diagnosis and prompt initiation of combination antimicrobials may improve clinical outcomes.

Methods

In this study, we sequenced a full draft assembly of the Balamuthia mandrillaris genome (44.2 Mb in size) from a rare survivor of PAM, and recovered the mitochondrial genome from six additional Balamuthia strains. We also used unbiased metagenomic next-generation sequencing (NGS) and SURPI bioinformatics analysis to diagnose an ultimately fatal case of Balamuthia mandrillaris encephalitis in a 15-year-old girl.

Results and Discussion

Comparative analysis of the mitochondrial genome and high-copy number genes from six additional Balamuthia mandrillaris strains demonstrated remarkable sequence variation, and the closest Balamuthia homologs corresponded to other amoebae, hydroids, algae, slime molds, and peat moss. Real-time NGS testing of hospital day 6 CSF and brain biopsy samples detected Balamuthia on the basis of high-quality hits to 16S and 18S ribosomal RNA sequences present in the National Center for Biotechnology Information (NCBI) nt reference database. The presumptive diagnosis of PAM by visualization of amoebae on brain biopsy histopathology and NGS analysis was subsequently confirmed at the US Centers for Disease Control and Prevention (CDC) using a Balamuthia-specific PCR assay. Retrospective analysis of a day 1 CSF sample revealed that more timely identification of Balamuthia by metagenomic NGS, potentially resulting in a better clinical outcome, would have required availability of the complete genome sequence.

Conclusions

These results underscore the diverse evolutionary origins of Balamuthia mandrillaris, provide new targets for diagnostic assay development, and will facilitate further investigations of the biology and pathogenesis of this eukaryotic pathogen. The failure to identify PAM from a day 1 sample without a fully sequenced Balamuthia genome in the database highlights the critical importance of whole-genome reference sequences for microbial detection by metagenomic NGS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0235-2) contains supplementary material, which is available to authorized users.

A novel outbreak enterovirus D68 strain associated with acute flaccid myelitis cases in the USA (2012-14): a retrospective cohort study

BACKGROUND

Enterovirus D68 was implicated in a widespread outbreak of severe respiratory illness across the USA in 2014 and has also been reported sporadically in patients with acute flaccid myelitis. We aimed to investigate the association between enterovirus D68 infection and acute flaccid myelitis during the 2014 enterovirus D68 respiratory outbreak in the USA.

METHODS

Patients with acute flaccid myelitis who presented to two hospitals in Colorado and California, USA, between Nov 24, 2013, and Oct 11, 2014, were included in the study. Additional cases identified from Jan 1, 2012, to Oct 4, 2014, via statewide surveillance were provided by the California Department of Public Health. We investigated the cause of these cases by metagenomic next-generation sequencing, viral genome recovery, and enterovirus D68 phylogenetic analysis. We compared patients with acute flaccid myelitis who were positive for enterovirus D68 with those with acute flaccid myelitis but negative for enterovirus D68 using the two-tailed Fisher's exact test, two-sample unpaired t test, and Mann-Whitney U test.

FINDINGS

48 patients were included: 25 with acute flaccid myelitis, two with enterovirus-associated encephalitis, five with enterovirus-D68-associated upper respiratory illness, and 16 with aseptic meningitis or encephalitis who tested positive for enterovirus. Enterovirus D68 was detected in respiratory secretions from seven (64%) of 11 patients comprising two temporally and geographically linked acute flaccid myelitis clusters at the height of the 2014 outbreak, and from 12 (48%) of 25 patients with acute flaccid myelitis overall. Phylogenetic analysis revealed that all enterovirus D68 sequences associated with acute flaccid myelitis grouped into a clade B1 strain that emerged in 2010. Of six coding polymorphisms in the clade B1 enterovirus D68 polyprotein, five were present in neuropathogenic poliovirus or enterovirus D70, or both. One child with acute flaccid myelitis and a sibling with only upper respiratory illness were both infected by identical enterovirus D68 strains. Enterovirus D68 viraemia was identified in a child experiencing acute neurological progression of his paralytic illness. Deep metagenomic sequencing of cerebrospinal fluid from 14 patients with acute flaccid myelitis did not reveal evidence of an alternative infectious cause to enterovirus D68.

INTERPRETATION

These findings strengthen the putative association between enterovirus D68 and acute flaccid myelitis and the contention that acute flaccid myelitis is a rare yet severe clinical manifestation of enterovirus D68 infection in susceptible hosts.

FUNDING

National Institutes of Health, University of California, Abbott Laboratories, and the Centers for Disease Control and Prevention.

Acute flaccid paralysis with anterior myelitis - California, June 2012-June 2014

In August 2012, the California Department of Public Health (CDPH) was contacted by a San Francisco Bay area clinician who requested poliovirus testing for an unvaccinated man aged 29 years with acute flaccid paralysis (AFP) associated with anterior myelitis (i.e., evidence of inflammation of the spinal cord involving the grey matter including anterior horn cell bodies) and no history of international travel during the month before symptom onset. Within 2 weeks, CDPH had received reports of two additional cases of AFP with anterior myelitis of unknown etiology. Testing at CDPH's Viral and Rickettsial Disease Laboratory for stool, nasopharyngeal swab, and cerebrospinal fluid (CSF) did not detect the presence of an enterovirus (EV), the genus of the family Picornaviridae that includes poliovirus. Additional laboratory testing for infectious diseases conducted at the CDPH Viral and Rickettsial Disease Laboratory did not identify a causative agent to explain the observed clinical syndrome reported among the patients. To identify other cases of AFP with anterior myelitis and elucidate possible common etiologies, CDPH posted alerts in official communications for California local health departments during December 2012, July 2013, and February 2014. Reports of cases of neurologic illness received by CDPH were investigated throughout this period, and clinicians were encouraged to submit clinical samples for testing. A total of 23 cases of AFP with anterior myelitis of unknown etiology were identified. Epidemiologic and laboratory investigation did not identify poliovirus infection as a possible cause for the observed cases. No common etiology was identified to explain the reported cases, although EV-D68 was identified in upper respiratory tract specimens of two patients. EV infection, including poliovirus infection, should be considered in the differential diagnosis in cases of AFP with anterior myelitis and testing performed per CDC guidelines.