Development of early‐born γ‐Aminobutyric acid hub neurons in mouse hippocampus from embryogenesis to adulthood

Early‐born γ‐aminobutyric acid (GABA) neurons (EBGNs) are major components of the hippocampal circuit because at early postnatal stages they form a subpopulation of “hub cells” transiently supporting CA3 network synchronization (Picardo et al. [2011] Neuron 71:695–709). It is therefore essential to determine when these cells acquire the remarkable morphofunctional attributes supporting their network function and whether they develop into a specific subtype of interneuron into adulthood. Inducible genetic fate mapping conveniently allows for the labeling of EBGNs throughout their life. EBGNs were first analyzed during the perinatal week. We observed that EBGNs acquired mature characteristics at the time when the first synapse‐driven synchronous activities appeared in the form of giant depolarizing potentials. The fate of EBGNs was next analyzed in the adult hippocampus by using anatomical characterization. Adult EBGNs included a significant proportion of cells projecting selectively to the septum; in turn, EBGNs were targeted by septal and entorhinal inputs. In addition, most EBGNs were strongly targeted by cholinergic and monoaminergic terminals, suggesting significant subcortical innervation. Finally, we found that some EBGNs located in the septum or the entorhinal cortex also displayed a long‐range projection that we traced to the hippocampus. Therefore, this study shows that the maturation of the morphophysiological properties of EBGNs mirrors the evolution of early network dynamics, suggesting that both phenomena may be causally linked. We propose that a subpopulation of EBGNs forms into adulthood a scaffold of GABAergic projection neurons linking the hippocampus to distant structures. J. Comp. Neurol. 524:2440–2461, 2016. © 2016 Wiley Periodicals, Inc.     

Correlation between plasma Flt3-ligand concentration and hematopoiesis during G-CSF-induced CD34+ cell mobilization

This study aimed to correlate blood Flt3-ligand (FL) concentration with CD34(+) cell number in blood and bone marrow (BM) during granulocyte colony-stimulating factor (G-CSF) mobilization. Nonhuman primates were injected with 10 microg/kg of G-CSF (Lenograstim) daily over a period of 5 days. Daily blood sampling and repeated BM sampling showed that FL concentration before mobilization was negatively correlated to the absolute number of BM CD34(+) cells, but also to the number of G-CSF-mobilized CD34(+) cells on days 3-5 of treatment. This showed that FL concentration in the blood reflected BM status before mobilization, and suggested that this parameter could be used as a predictive indicator of G-CSF-induced CD34(+) cell mobilization.     

PNPLA3 and TM6SF2 variants as risk factors of hepatocellular carcinoma across various etiologies and severity of underlying liver diseases

Few single nucleotide polymorphisms (SNPs) have been reproducibly associated with hepatocellular carcinoma (HCC). Our aim was to test the association between nine SNPs and HCC occurrence. SNPs in genes linked to HCC (DEPDC5, GRIK1, KIF1B, STAT4, MICA, DLC1, DDX18) or to liver damage (PNPLA3-rs738409, TM6SF2-rs58542926) in GWAS were genotyped in discovery cohorts including 1,020 HCC, 2,021 controls with chronic liver disease and 2,484 healthy individuals and replication was performed in prospective cohorts of cirrhotic patients with alcoholic liver disease (ALD, n = 249) and hepatitis C (n = 268). In the discovery cohort, PNPLA3 and TM6SF2 SNPs were associated with HCC (OR = 1.67 [CI95%:1.16–2.40], p = 0.005; OR = 1.45 [CI95%:1.08–1.94], p = 0.01) after adjustment for fibrosis, age, gender and etiology. In contrast, STAT4-rs7574865 was associated with HCC only in HBV infected patients (p = 0.03) and the other tested SNP were not linked with HCC risk. PNPLA3 and TM6SF2 variants were independently associated with HCC in patients with ALD (OR = 3.91 [CI95%:2.52–6.06], p = 1.14E-09; OR = 1.79 [CI95%:1.25–2.56], p = 0.001) but not with other etiologies. PNPLA3 SNP was also significantly associated with HCC developed on a nonfibrotic liver (OR = 2.19 [CI95%:1.22–3.92], p = 0.007). The association of PNPLA3 and TM6SF2 with HCC risk was confirmed in the prospective cohort with ALD. A genetic score including PNPLA3 and TM6SF2 minor alleles showed a progressive significant increased risk of HCC in ALD patients. In conclusion, PNPLA3-rs738409 and TM6SF2-rs58542926 are inherited risk variants of HCC development in patients with ALD in a dose dependent manner. The link between PNPLA3 and HCC on nonfibrotic liver suggests a direct role in liver carcinogenesis.     

Can failure of percutaneous drainage of postoperative abdominal abscesses be predicted?

BACKGROUND: Percutaneous drainage (PD) of complex postoperative abscesses associated with a variety of factors such as multiple location or enteric fistula remains a matter of debate. Accordingly, this retrospective study was designed to determine the predictive factors for failure of PD of postoperative abscess, in order to better select the patients who may benefit from PD. METHODS: From 1992 to 2000, the data of 73 patients who underwent computed tomography (CT)-guided PD for postoperative intra-abdominal abscess, were reviewed. PD was considered as failure when clinical sepsis persisted or subsequent surgery was needed. The possible association between failure of PD and 27 patient-, abscess-, surgical-, and drainage-related variables were assessed using univariate and multivariate analysis. RESULTS: Successful PD was achieved in 59 of 73 (81%) patients. The overall mortality was 3% but no patient died after salvage surgery. Multivariate analysis showed that only an abscess diameter of less than 5 cm (P = 0.042) and absence of antibiotic therapy (P = 0.01) were significant predictive variables for failure of PD. CONCLUSIONS: CT-guided PD associated with antibiotic therapy could be attempted as the initial treatment of postoperative abdominal abscesses even in complex cases such as loculated abscess or abscess associated with enteric fistula.     

Inter-center reproducibility of standard and advanced echocardiographic parameters in the EACVI-AFib echo registry

Aim

we sought to test the inter-center reproducibility of 16 echo laboratories involved in the EACVI-Afib Echo Europe.

Methods

This was done on a dedicated setting of 10 patients with sinus rhythm (SR) and 10 with persistent atrial fibrillation (AF), collected by the Principal Investigator. Images and loops of echo-exams were stored and made available for labs. The tested measurements included main echo-Doppler parameters, global longitudinal strain (GLS) and peak atrial longitudinal strain (PALS).

Results

Single measures interclass correlation coefficients (ICCs) of left ventricular mass and ejection fraction were suboptimal in both patients with SR and AF. Among diastolic parameters, ICCs of deceleration time were poor, in particular in AF (=.50). ICCs of left atrial size and function, besides optimal in AF, showed an acceptable despite moderate concordance in SR. ICC of GLS was .81 and .78 in SR and AF respectively. ICCs of PALS were suitable but lower in 4-chamber than in 2-chamber view. By depicting the boxplot of the 16 laboratories, GLS distribution was completely homogeneous in SR, whereas GLS of AF and PALS of both SR and AF presented a limited number of outliers. GLS mean ± SE of the 16 labs was 19.7 ± .36 (95% CI: 18.8-20.4) in SR and 16.5 ± .29 (95% CI: 15.9-17.1) in AF, whereas PALS mean ± SE was 43.8 ± .70 (95% CI: 42.3-45.3) and 10.2 ± .32 (95% CI: 9.5-10.9) respectively.

Conclusion

While the utilization of some standard-echo variables should be discouraged in registries, the application of GLS and PALS could be largely promoted because their superior reproducibility, even in AF.     

GRK2-Targeted Knockdown as Therapy for Multiple System Atrophy

Background

Multiple system atrophy (MSA) is a sporadic adult-onset rare neurodegenerative synucleinopathy for which counteracting central nervous system insulin resistance bears the potential of being neuroprotective. G-protein-(heterotrimeric guanine nucleotide-binding protein)-coupled receptor kinase 2 (GRK2) is emerging as a physiologically relevant inhibitor of insulin signaling.

Objectives

We tested whether lowering brain GRK2 abundance may reverse insulin-resistance.

Methods

We lowered brain GRK2 abundance through viral-mediated delivery of a GRK2-specific miRNA and quantified the reversion of a developing or an established insulin-resistant phenotype using the transgenic PLP-SYN mouse model of MSA.

Results

Viral vector delivery of a GRK2 miRNA demonstrated a neuroprotective capacity when administered (1) in utero intracerebroventricularly in developing PLP-SYN mice and (2) intrastriatally in adult PLP-SYN mice. Decreased striatal GRK2 levels correlated in both designs with neuroprotection of the substantia nigra dopamine neurons, reduction in high-molecular-weight species of α-synuclein, and reduced insulin resistance.

Conclusions

These data support GRK2 as a potential therapeutic target in MSA. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.     

Role of aldosterone in mid- and long-term left ventricular remodelling after acute myocardial infarction: The REMI study

Aims

Whether aldosterone levels after myocardial infarction (MI) are associated with mid- and long-term left ventricular (LV) remodelling in the era of systematic use of renin–angiotensin system inhibitors is uncertain. We prospectively investigated the relationship between aldosterone levels and mid- and long-term LV remodelling in patients with acute MI.

Methods and results

Plasma aldosterone was measured in 119 patients successfully treated by primary percutaneous coronary angioplasty for a first acute ST-elevation MI (STEMI) 2–4 days after the acute event. LV volumes were assessed by cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE) in the same timeframe and 6 months later. LV assessment was repeated by TTE 3–9 years after MI (n = 80). The median aldosterone level at baseline was 23.1 [16.8; 33.1] pg/ml. In the multivariable model, higher post-MI aldosterone concentration was significantly associated with more pronounced increase in LV end-diastolic volume index (TTE: β ± standard error [SE]: 0.113 ± 0.046, p = 0.015; CMR: β ± SE: 0.098 ± 0.040, p = 0.015) and LV end-systolic volume index (TTE: β ± SE: 0.083 ± 0.030, p = 0.008; CMR: β ± SE: 0.064 ± 0.032, p = 0.048) at 6-month follow-up, regardless of the method of assessment. This result was consistent also in patients with a LV ejection fraction (LVEF) >40%. The association between baseline plasma aldosterone and adverse LV remodelling did not persist at the 3–9-year follow-up evaluation.

Conclusion

Aldosterone concentration in the acute phase was associated with adverse LV remodelling in the medium term, even in the subgroup of patients with LVEF >40%, suggesting a potential role of the mineralocorticoid system in post-MI adverse remodelling. Plasma aldosterone was no longer associated with LV remodelling in the long term (NCT01109225).