Transcranial brain parenchyma sonography in patients with juvenile myoclonic epilepsy.

INTRODUCTION: There are rising evidences that subcortical structures, including the basal ganglia, are affected in patients with epilepsy. These structures are thought to influence the modulation and phenotypic expression of epileptic seizures. Our study aimed to evaluate the presence of structural abnormalities in subcortical structures in patients with juvenile myoclonic epilepsy (JME). METHODS: This cross-sectional study included 51 patients who were diagnosed with JME and who were monitored on an outpatient basis at the Clinic for Neurology and Psychiatry for Children and Youth in Belgrade from January 1985 to October 2017. All patients underwent transcranial parenchymal sonography (TCS) from October 2015 to October 2017. Relation of clinical parameters (seizure control andcognitive functioning,) with TCS results was assessed. RESULTS: Hyperechogenicity of the substantia nigra (SN) was detected in 37.2% of JME subjects and it was significantly more common in patients with JME than in the control group. The marked echogenicity of the red nucleus (RN) was detected in 17.6% of cases, while 11.8% of subjects had hyperechogenic RN. The presence of hyperechogenic RN (both right and left) was significantly more frequent in the group of patients with JME compared to the control group. The third ventricle diameter was larger in patients with JME than in controls. CONCLUSION: Structural changes of certain subcortical structures, primarily SN and RN, detected in JME patients indicate additional non-lesional abnormalities of the basal ganglia and midbrain structures in these patients.

PIEZO1 is essential for the survival and proliferation of acute myeloid leukemia cells.

INTRODUCTION: Leukemogenesis is a complex process that interconnects tumoral cells with their microenvironment, but the effect of mechanosensing in acute myeloid leukemia (AML) blasts is poorly known. PIEZO1 perceives and transmits the constraints of the environment to human cells by acting as a non-selective calcium channel, but very little is known about its role in leukemogenesis. RESULTS: For the first time, we show that PIEZO1 is preferentially expressed in healthy hematopoietic stem and progenitor cells in human hematopoiesis, and globally overexpressed in AML cells. In AML subtypes, PIEZO1 expression associates with favorable outcomes as better overall (OS) and disease-free survival (DFS). If PIEZO1 is expressed and functional in THP1 leukemic myeloid cell line, its chemical activation doesn't impact the proliferation, differentiation, nor survival of cells. However, the downregulation of PIEZO1 expression dramatically reduces the proliferation and the survival of THP1 cells. We show that PIEZO1 knock-down blocks the cell cycle in G0/G1 phases of AML cells, impairs the DNA damage response pathways, and critically increases cell death by triggering extrinsic apoptosis pathways. CONCLUSIONS: Altogether, our results reveal a new role for PIEZO1 mechanosensing in the survival and proliferation of leukemic blasts, which could pave the way for new therapeutic strategies to target AML cells.

STIM2 is involved in the regulation of apoptosis and the cell cycle in normal and malignant monocytic cells.

Calcium is a ubiquitous messenger that regulates a wide range of cellular functions, but its involvement in the pathophysiology of acute myeloid leukemia (AML) is not widely investigated. Here, we identified, from an analysis of The Cancer Genome Atlas and genotype-tissue expression databases, stromal interaction molecule 2 (STIM2) as being highly expressed in AML with monocytic differentiation and negatively correlated with overall survival. This was confirmed on a validation cohort of 407 AML patients. We then investigated the role of STIM2 in cell proliferation, differentiation, and survival in two leukemic cell lines with monocytic potential and in normal hematopoietic stem cells. STIM2 expression increased at the RNA and protein levels upon monocyte differentiation. Phenotypically, STIM2 knockdown drastically inhibited cell proliferation and induced genomic stress with DNA double-strand breaks, as shown by increased levels of phosphorylate histone H2AXγ (p-H2AXγ), followed by activation of the cellular tumor antigen p53 pathway, decreased expression of cell cycle regulators such as cyclin-dependent kinase 1 (CDK1)-cyclin B1 and M-phase inducer phosphatase 3 (CDC25c), and a decreased apoptosis threshold with a low antiapoptotic/proapoptotic protein ratio. Our study reports STIM2 as a new actor regulating genomic stability and p53 response in terms of cell cycle and apoptosis of human normal and malignant monocytic cells.

Immediate results of primary balloon dilation for congenital aortic valve stenosis predict the mid-term outcome.

BACKGROUND: Balloon valvuloplasty is the primary treatment for congenital aortic valve stenosis in our centre. We sought to determine independent predictors of reintervention (surgical repair or repeated balloon dilation) after primary valvuloplasty. METHODS: We retrospectively studied patients with congenital aortic valve stenosis who underwent balloon valvuloplasty during 2004-2018. The following risk factors were analysed: aortic valve insufficiency after balloon valvuloplasty >+1/4, post-procedural gradient across the aortic valve ≥35 mmHg, pre-interventional gradient across the valve, annulus size, use of rapid pacing, and balloon/annulus ratio. Primary outcome was aortic valve reintervention. RESULTS: In total, 99 patients (median age 4 years, range 1 day to 26 years) underwent balloon valvuloplasty for congenital aortic valve stenosis. After a mean follow-up of 4.0 years, 30% had reintervention. Adjusted risks for reintervention were significantly increased in patients with post-procedural aortic insufficiency grade >+1/4 and/or residual gradient ≥35 mmHg (HR 2.55, 95% CI 1.13-5.75, p = 0.024). Pre-interventional gradient, annulus size, rapid pacing, and balloon/annulus ratio were not associated with outcome. CONCLUSION: Post-procedural aortic valve insufficiency grade >+1/4 and/or residual gradient ≥35 mmHg in patients undergoing balloon valvuloplasty for congenital aortic valve stenosis confers an increased risk for reintervention in mid-term follow-up.

HDAC6 regulates human erythroid differentiation through modulation of JAK2 signalling.

Among histone deacetylases, HDAC6 is unusual in its cytoplasmic localization. Its inhibition leads to hyperacetylation of non-histone proteins, inhibiting cell cycle, proliferation and apoptosis. Ricolinostat (ACY-1215) is a selective inhibitor of the histone deacetylase HDAC6 with proven efficacy in the treatment of malignant diseases, but anaemia is one of the most frequent side effects. We investigated here the underlying mechanisms of this erythroid toxicity. We first confirmed that HDAC6 was strongly expressed at both RNA and protein levels in CD34+ -cells-derived erythroid progenitors. ACY-1215 exposure on CD34+ -cells driven in vitro towards the erythroid lineage led to a decreased cell count, an increased apoptotic rate and a delayed erythroid differentiation with accumulation of weakly hemoglobinized immature erythroblasts. This was accompanied by drastic changes in the transcriptomic profile of primary cells as shown by RNAseq. In erythroid cells, ACY-1215 and shRNA-mediated HDAC6 knockdown inhibited the EPO-dependent JAK2 phosphorylation. Using acetylome, we identified 14-3-3ζ, known to interact directly with the JAK2 negative regulator LNK, as a potential HDAC6 target in erythroid cells. We confirmed that 14-3-3ζ was hyperacetylated after ACY-1215 exposure, which decreased the 14-3-3ζ/LNK interaction while increased LNK ability to interact with JAK2. Thus, in addition to its previously described role in the enucleation of mouse fetal liver erythroblasts, we identified here a new mechanism of HDAC6-dependent control of erythropoiesis through 14-3-3ζ acetylation level, LNK availability and finally JAK2 activation in response to EPO, which is crucial downstream of EPO-R activation for human erythroid cell survival, proliferation and differentiation.

Protein-losing enteropathy managed with percutaneous enlargement of a restrictive atrial septal defect.

Protein-losing enteropathy is one of the most feared complications of the Fontan circulation. The diagnosis of protein-losing enteropathy in this setting should prompt a thorough investigation for the presence of a treatable hemodynamic impairment. In this report, we describe a complete reversal of protein-losing enteropathy following percutaneous enlargement of a restrictive atrial septal defect in a patient with a fenestrated lateral tunnel Fontan and severe mitral stenosis.

Recent advances in the pathophysiology of PIEZO1-related hereditary xerocytosis.

Hereditary xerocytosis is a rare red blood cell disease related to gain-of-function mutations in the FAM38A gene, encoding PIEZO1, in 90% of cases; PIEZO1 is a broadly expressed mechano-transducer that plays a major role in many cell systems and tissues that respond to mechanical stress. In erythrocytes, PIEZO1 adapts the intracellular ionic content and cell hydration status to the mechanical constraints induced by the environment. Until recently, the pathophysiology of hereditary xerocytosis was mainly believed to be based on the "PIEZO1-Gardos channel axis" in erythrocytes, according to which PIEZO1-activating mutations induce a calcium influx that secondarily activates the Gardos channel, leading to potassium and water efflux and subsequently to red blood cell dehydration. However, recent studies have demonstrated additional roles for PIEZO1 during early erythropoiesis and reticulocyte maturation, as well as roles in other tissues and cells such as lymphatic vessels, hepatocytes, macrophages and platelets that may affect the pathophysiology of the disease. These findings, presented and discussed in this review, broaden our understanding of hereditary xerocytosis beyond that of primarily being a red blood cell disease and identify potential therapeutic targets.

Glucose and lipid metabolism disorders in children and adolescents with spinal muscular atrophy types 2 and 3.

We aimed to estimate the prevalence of glucose and lipid metabolism disorders in children and adolescents with spinal muscular atrophy (SMA) types 2 and 3. A cross-sectional study was conducted. Medical history, anthropometric measurements, pubertal status, blood chemistry (glucose and insulin levels, lipid profile, aminotransferases, and hemoglobin A1c [HbA1c]), and liver ultrasound were obtained in all patients. Oral glucose tolerance test was performed in those with body mass index (BMI) >25th percentile or glucose or HbA1c levels in the prediabetic range. A total of 37 patients with SMA (22 type 2, 15 type 3) with a median age of 8.5 years (range 2-18.9 years) were included. Eleven patients (29.7%) met the criteria for prediabetes, but none had overt type 2 diabetes. Dyslipidemia was detected in 11 patients (29.7%), and 4 (10.8%) had hepatic steatosis on ultrasound. Sixteen patients (43.2%) had at least one abnormal finding (prediabetes, dyslipidemia, or hepatic steatosis); all but one were non-ambulatory and 12 (75%) had BMI ≥85th percentile. One young child developed fasting hypoglycemia. Our results suggest that non-ambulatory overweight/obese SMA patients are particularly prone to abnormalities in glucose and lipid metabolism. Young underweight patients might develop fasting hypoglycemia.

Cardiac findings in pediatric patients with spinal muscular atrophy types 2 and 3.

BACKGROUND: It is unclear whether the heart is affected in pediatric patients with milder forms of spinal muscular atrophy (SMA). Therefore, we aimed to determine the presence of any cardiac abnormalities in these patients. METHODS: We conducted a cross-sectional study of children and adolescents with SMA types 2 and 3 between July 2018 and July 2019. All patients underwent a comprehensive cardiac evaluation, including history-taking, physical examination, electrocardiography, echocardiography, measurement of cardiac biomarkers (cardiac troponin T [cTnT] and N-terminal pro-brain natriuretic peptide [NT-proBNP]), and 24-hour Holter monitoring. RESULTS: In total, 42 patients were enrolled (27 and 15 with SMA type 2 and 3, respectively). No patient had structural heart disease, except for one with mitral valve prolapse. None had signs of ventricular dysfunction on echocardiography. Both cTnT and NT-proBNP levels were normal in all patients. Electrocardiography showed sinus tachycardia in seven patients (16.7%), and prolonged P-R interval in one (2.4%). Holter monitoring detected benign ventricular arrhythmias in two patients (4.8%), and rare supraventricular premature beats in one. The mean 24-hour heart rate was elevated in six patients (14.3%), whereas both the minimum 24-hour heart rate and the maximum R-R interval were increased in 23 (54.8%). DISCUSSION: The prevalence of cardiac disease in pediatric patients with SMA types 2 and 3 is low; however, these patients may have increased resting heart rates. A complete cardiac history and physical examination are a useful screen. Additional cardiac investigations may be performed as needed.

Transcatheter closure of a residual aorto-left ventricular tunnel: report of a case with a 6-year follow-up.

Aorto-left ventricular tunnel is an exceedingly rare congenital cardiac defect. Early surgical closure is the treatment of choice. Residual or recurrent tunnel and aortic valve insufficiency are well-recognised complications after surgical repair. In this article, we report on successful transcatheter closure of a residual aorto-left ventricular tunnel using an Amplatzer duct occluder in a 7-year-old boy. The outcome after 6 years of follow-up is encouraging.

Cardiac haemangioma associated with a duct-dependent congenital heart disease in a newborn infant.

Cardiac haemangiomas are exceedingly rare; however, they can cause significant haemodynamic impairment and disturbances in heart rhythm. Rarely, cardiac tumours may also coexist with congenital heart lesions. We present an extremely unusual case of a cardiac haemangioma in the setting of complex transposition of the great arteries that caused functional tricuspid atresia. To our knowledge, this is the first such case described in the literature.