Effects of evolocumab on plasma levels of proprotein convertase subtilisin/kexin type 9 and lipoprotein(a) in acute myocardial infarction

Background

There are two types of circulating proprotein convertase subtilisin/kexin type 9 (PCSK9), mature and furin-cleaved. Most types of lipoprotein(a) [Lp(a)], an independent risk factor of cardiovascular events, bound to mature PCSK9.

Purpose

This study examined the effects of monoclonal anti-PCSK9 antibody on plasma PCSK9 and Lp(a) levels in acute myocardial infarction (MI).

Methods

Acute MI patients (n=36) were randomly divided into evolocumab (140 mg; n=17) and non-evolocumab (n=19) groups. Changes in plasma PCSK9 and Lp(a) levels were monitored before and 1, 3, 5, 10, and 20 days after evolocumab administration.

Results

In the non-evolocumab group, plasma levels of mature PCSK9, furin-cleaved PCSK9, and Lp(a) (236.4±57.3 ng/mL, 22.4±5.8 ng/mL, and 19.2. ± 16.5 mg/dL, respectively) significantly increased by day 3 (408.8±77.1 ng/mL, P<0.001; 47.2±15.7 ng/mL, P<0.001; and 39.7±21.3 mg/dL, P<0.005, respectively) and returned to the baseline by day 10 or 20. In the evolocumab group, mature PCSK9 significantly increased by >1000 ng/mL with a simultaneous decline of furin-cleaved PCSK9 below the measurement sensitivity level after day 3. The incremental area under the curve for plasma Lp(a) levels was significantly smaller in the evolocumab group compared with the non-evolocumab group (P=0.038).

Conclusion

Mature and furin-cleaved PCSK9 are transiently upregulated after MI onset. Evolocumab significantly increases mature PCSK9 and decreases furin-cleaved PCSK9 and might inhibit transient increase of plasma Lp(a) in acute MI.

Figure 1

Funding Acknowledgement

Type of funding source: None

Chronotropic incompetence and exercise capacity after mitral valve surgery: the importance of blood hemoglobin level

Background

Chronotropic incompetence (CI) is sometimes observed during exercise training of cardiac rehabilitation in patients with cardiac surgery, however, little is known concerning the differences between patients with mitral valve (MV) and aortic valve (AV) surgery.

Purpose

Because the possibility exists that cardiac sympathetic nerves might be impaired by left atrium incision, we hypothesized that the incidence of CI was higher in patients with MV surgery (Mitral Valve Replacement and Mitral Valvuloplasty) as compared with patients with AV surgery (Aortic Valve Replacement). And if so, which factor determines the exercise capacity of patients after MV surgery. We thus aimed this study to elucidate the hypothesis with cardiopulmonary exercise testing (CPX).

Methods

We performed CPX by ramp loading with ergometer exercise in total 61 patients who had undergone elective cardiac valve operation (25 patients with MV surgery, age 59.2±9.9 years; 36 patients with AV surgery, age 64.6±12.3 years). We analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), and peak oxygen pulse (peak VO2/HR) with CPX, and blood hemoglobin concentration (Hb).

Results

The value of CRI was significantly decreased in the patients with MV surgery compared with those with AV surgery (MV; 0.19±0.10 vs. AV; 0.41±0.17, p<0.001). Peak VO2, peak VO2/HR and Hb were not significantly different between patients with MV and those with AV surgery. Patients with MV surgery showed correlations between peak VO2 and Hb (r=0.45, p<0.05), AT and Hb (r=0.52, p<0.01), and a strong correlation between peak VO2 and peak VO2/HR (r=0.63, p<0.001), but not in those with AV surgery.

Conclusions

The present study demonstrated that higher incidence of CI was shown in patients with MV surgery as compared with those with AV surgery. The exercise capacity of patients with MV surgery was determined by peak VO2/HR and Hb. These results suggest that 1) left atrium incision impairs cardiac sympathetic nerves and causes CI, 2) peak VO2/HR which is consisted of arterio-venous oxygen difference and Hb is critical indicator for exercise capacity in patients with MV surgery with CI.

Main results

Funding Acknowledgement

Type of funding source: None

Magnetic and transport properties of new ternary uranium-based germanide U2Rh3Ge5

A new ternary uranium germanide U₂Rh₃Ge₅ has been successfully synthesized and investigated by means of magnetic susceptibility χ(T, H), isothermal magnetization M(T, H), electrical resistivity ρ(T), and specific heat C(T, H) measurements. This compound is found to crystallize in the U₂Co₃Si₅-type orthorhombic structure. The low-field χ(T) shows a clear peak at T _N = 41.5 K corresponding to an antiferromagnetic transition. The M(H) curve measured up to 70 kOe exhibits an H-linear behavior at 2 K with very small induced magnetic moments, while it shows upward curvature with increasing temperature, implying the possible presence of a metamagnetic transition in high-field region above 70 kOe. As the temperature decreases, ρ(T) increases slowly at T > T _N and decreases rapidly at T < T _N, which can be understood based on a semiconductor-like narrow band gap model (or the c-f hybridization effect) and an antiferromagnetic spin-wave model, respectively. No evidence of heavy-fermion behavior or superconductivity transition is observed at temperatures as low as 0.4 K. The obtained experimental results are discussed by comparing with those reported for the isomorphic compound U₂Ir₃Si₅ and the quasi-isomorphic compound U₂Rh₃Si₅.

Suppressing dynamical diffraction artefacts in differential phase contrast scanning transmission electron microscopy of long-range electromagnetic fields via precession

It is well known that dynamical diffraction varies with changes in sample thickness and local crystal orientation (due to sample bending). In differential phase contrast scanning transmission electron microscopy (DPC-STEM), this can produce contrast comparable to that arising from the long-range electromagnetic fields probed by this technique. Through simulation we explore the scale of these dynamical diffraction artefacts and introduce a metric for the magnitude of their contribution to the contrast. We show that precession over an angular range of a few milliradian can suppress this contribution to the contrast by one-to-two orders of magnitude. Our exploration centres around a case study of GaAs near the [011] zone-axis orientation using a probe-forming aperture semiangle on the order of 0.1 mrad at 300 keV, but the trends found and methodology used are expected to apply more generally.

Monitoring the autophagy-endolysosomal system using monomeric Keima-fused MAP1LC3B

The autophagy-endolysosomal pathway is an evolutionally conserved degradation system that is tightly linked to a wide variety of physiological processes. Dysfunction of this system is associated with many pathological conditions such as cancer, inflammation and neurodegenerative diseases. Therefore, monitoring the cellular autophagy-endolysosomal activity is crucial for studies on the pathogenesis as well as therapeutics of such disorders. To this end, we here sought to create a novel means exploiting Keima, an acid-stable fluorescent protein possessing pH-dependent fluorescence excitation spectra, for precisely monitoring the autophagy-endolysosomal system. First, we generated three lines of transgenic (tg) mouse expressing monomeric Keima-fused MAP1LC3B (mKeima-LC3B). Then, these tg mice were subjected to starvation by food-restriction, and also challenged to neurodegeneration by genetically crossing with a mouse model of amyotrophic lateral sclerosis; i.e., SOD1^H46R transgenic mouse. Unexpectedly, despite that a lipidated-form of endogenous LC3 (LC3-II) was significantly increased, those of mKeima-LC3B (mKeima-LC3B-II) were not changed under both stressed conditions. It was also noted that mKeima-LC3B-positive aggregates were progressively accumulated in the spinal cord of SOD1^H46R;mKeima-LC3B double-tg mice, suggestive of acid-resistance and aggregate-prone natures of long-term overexpressed mKeima-LC3B in vivo. Next, we characterized mouse embryonic fibroblasts (MEFs) derived from mKeima-LC3B-tg mice. In contrast with in vivo, levels of mKeima-LC3B-I were decreased under starved conditions. Furthermore, when starved MEFs were treated with chloroquine (CQ), the abundance of mKeima-LC3B-II was significantly increased. Remarkably, when cultured medium was repeatedly changed between DMEM (nutrient-rich) and EBSS (starvation), acidic/neutral signal ratios of mKeima-LC3B-positive compartments were rapidly and reversibly shifted, which were suppressed by the CQ treatment, indicating that intraluminal pH of mKeima-LC3B-positive vesicles was changeable upon nutritional conditions of culture media. Taken together, although mKeima-LC3B-tg mice may not be an appropriate tool to monitor the autophagy-endolysosomal system in vivo, mKeima-LC3B must be one of the most sensitive reporter molecules for monitoring this system under in vitro cultured conditions.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Social inequalities of postpartum depression: the mediating role of social support during pregnancy

Introduction

A disadvantaged socioeconomic position (SEP), as well as insufficient social support during pregnancy (SSP) increase the probability of subsequent postpartum depression (PPD). The aim of this study was to quantify the part of social inequalities in PPD due to insufficient SSP and in particular assess the impact relative to women’s migrant status.

Methods

The sample included 15,000 women from the nationally representative French ELFE birth cohort study. Depressive symptoms were assessed at two months postpartum by the EPDS. SEP was constructed as a latent factor explaining educational level, occupational grade, employment during pregnancy, household income and financial difficulties. SSP was characterized by informal support (partner perceived support, frequency of quarrels and paternal leave) and formal support (early prenatal psychosocial risk assessment and antenatal classes’ attendance). Causal mediation analyses between SEP, dimensions of SSP and PPD were conducted and stratified on migrant status (categorized as native French, first or second generation migrant or immigrant).

Results

A disadvantaged SEP and a lack of informal SSP during pregnancy were both associated with an increased risk for postpartum depressive symptoms and a disadvantaged SEP was positively associated with lack of SSP. In immigrant women, a larger proportion of social inequalities in PPD could be attributed to lack of SSP, in comparison to native French women (17.5% vs. 8.8%).

Conclusions

Both disadvantaged SEP and SSP are risk factors for PPD. We found evidence that disadvantaged women’s increased risk for PPD can partly be attributed to limited social support.

Key messages

PPD in disadvantaged groups, especially in migrant women, could possibly be prevented early in pregnancy by increasing support from partner and larger family. Access to social support health care systems directed towards pregnant women remains low for women with a disadvantaged SEP, especially in migrant women.

A Novel Non-invasive Method for Predicting Liver Fibrosis by Quantifying the Hepatic Vein Waveform

The hepatic vein (HV) waveform by Doppler ultrasound reflects the severity of liver fibrosis. We conducted a proof-of-concept study of a new method for quantifying the HV waveform. We calculated the coefficient of variation (CV) of the HV flow velocity and created a new index "q-HV" (quantified HV) and analyzed its performance for predicting histologic liver fibrosis in 114 patients with chronic liver disease. The CV of the HV flow velocity was well associated with flattening of the waveform and the q-HV significantly increased with the progression of liver fibrosis. The areas under the curve for the prediction of fibrosis stage were 0.732 for F2, 0.772 for F3 and 0.805 for F4. Combined q-HV and FIB-4 index (widely used liver fibrosis score) increased the diagnostic accuracy for liver fibrosis. The q-HV showed good accuracy for predicting liver fibrosis; thus, q-HV is feasible and acceptable as a non-invasive tool for predicting liver fibrosis.

Creation of CRISPR-based germline-genome-engineered mice without ex vivo handling of zygotes by i-GONAD

Methods to create genetically engineered mice involve three major steps: harvesting embryos from one set of females, microinjection of reagents into embryos ex vivo and their surgical transfer to another set of females. Although tedious, these methods have been used for more than three decades to create mouse models. We recently developed a method named GONAD (genome editing via oviductal nucleic acids delivery), which bypasses these steps. GONAD involves injection of CRISPR components (Cas9 mRNA and guide RNA (gRNA)) into the oviducts of pregnant females 1.5 d post conception, followed by in vivo electroporation to deliver the components into the zygotes in situ. Using GONAD, we demonstrated that target genes can be disrupted and analyzed at different stages of mouse embryonic development. Subsequently, we developed improved GONAD (i-GONAD) by delivering CRISPR ribonucleoproteins (RNPs; Cas9 protein or Cpf1 protein and gRNA) into day-0.7 pregnant mice, which made it suitable for routine generation of knockout and large-deletion mouse models. i-GONAD can also generate knock-in models containing up to 1-kb inserts when single-stranded DNA (ssDNA) repair templates are supplied. i-GONAD offers other advantages: it does not require vasectomized males and pseudo-pregnant females, the females used for i-GONAD are not sacrificed and can be used for other experiments, it can be easily adopted in laboratories lacking sophisticated microinjection equipment, and can be implemented by researchers skilled in small-animal surgery but lacking embryo-handling skills. Here, we provide a step-by-step protocol for establishing the i-GONAD method. The protocol takes ∼6 weeks to generate the founder mice.

HER2-Positive Conversion in a Metastatic Liver Focus in Late Recurrent Breast Cancer

Late recurrence of estrogen receptor (ER) positive breast cancer is common. When tissues from a recurrent or metastatic focus are available, re-evaluation of ER, progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2) status is recommended for treatment selection. This case report describes a 59-year-old woman who underwent surgery for left breast cancer, with a histopathological diagnosis of invasive ductal carcinoma (pathological stage T2N1aM0 Stage IIB, ER positive, PgR positive and HER2 negative). A health check-up 16 years after surgery revealed multiple hepatic mass lesions, and the patient was referred to our hospital for tests. Based on computed tomography, intrahepatic bile duct cancer or metastatic hepatic tumors were suspected, and a liver biopsy was performed. The histopathological diagnosis was a poorly differentiated adenocarcinoma (ER negative, PgR negative and HER2 positive), and the distinction from poorly differentiated intrahepatic bile duct cancer was difficult. Fluorodeoxyglucose (FDG)-positron emission tomography revealed FDG accumulation in the patient's bones and soft tissues, in addition to the hepatic tumors. The patterns and finding of metastasis were compatible with breast cancer recurrence, and the patient was diagnosed with postoperative recurrence of left breast cancer. Pertuzumab, trastuzumab, and docetaxel were started, and the therapeutic effect was assessed as a partial response. It was evident that in this case, the expression of hormone receptors and HER2 differed between the primary focus and the recurrence foci, and this contributed to the treatment strategy. Whenever possible, a biopsy should be performed for lesions that are suspected to be distal metastases.