West Nile neuroinvasive disease. Report of four cases in Northern Greece, 2018.

West Nile virus (WNV) is a mosquito-borne RNA flavivirus which caused several epidemics worldwide. The year 2018 was a WNV record year for Europe, including Greece, with earlier and longer transmission season with higher than the previous number of cases. It has been proposed that some simple biochemical markers may be helpful for the recognition of WNV neuroinvasive disease, its differential from other neurological infectious diseases and prognosis. We describe four cases that suffered from WNV meningitis and/or encephalitis hospitalized in 2018 in a tertiary hospital in Thessaloniki, Greece, and investigate the importance of simple biomarkers for the recognition of WNV etiology.

Rapid right ventricular pacing for balloon aortic valvuloplasty: expanding its routine use in neonates and infants.

OBJECTIVE: Rapid right ventricular pacing during balloon aortic valvuloplasty is commonly used to achieve balloon stability in children and adults. There is no consensus for the use of the technique in neonates and infants. We sought to review our institutional experience with rapid right ventricular pacing-assisted balloon aortic valvuloplasty across all age groups and evaluate the safety and effectiveness of the technique in the sub-group of neonates and infants <12months. METHODS: Retrospective study between February, 2011 and February, 2020. RESULTS: A total of 37 patients (Group I: 21 neonates/infants <12months and Group II: 16 children 12 months-16 years) were analysed. Catheter-measured left ventricular to aortic gradient reduced from median of 66 mmHg (with a range from 30 to 125 mmHg) to 14 mmHg (with a range from 5 to 44 mmHg) in Group I and 44 mmHg (with a range from 28 to 93 mmHg) to 18 mmHg (with a range from 2 to 65 mmHg) in Group II (p < 0.001). Procedure and fluoroscopy times were identical in the two groups. Balloon:annulus ratio was 0.94 and 0.88 in Groups I and II, respectively. Freedom from reintervention was 100% for Group I at a median time of 3.2 years and 81% at 2.7 years for Group II. Reinterventions in Group II (3/16 pts) were performed predominantly for complex left ventricular outflow tract stenosis. At follow-up echocardiogram, 45% of patients in Group I had no aortic regurgitation, 30% trace-mild, 20% mild-moderate, and 5% moderate aortic regurgitation, whereas in Group II, 50% of patients had no aortic regurgitation, 32% had mild aortic regurgitation, and 18% mild-moderate aortic regurgitation. Unicuspid valves were only encountered in Group 1 (2/21 pts, 10%) and they were predictive of mild-aortic regurgitation during follow-up (p = 0.003). Ventricular fibrillation occurred in three neonates with suspicion of myocardial ischemia on the pre-procedure echocardiogram. All were successfully defibrillated. CONCLUSIONS: Rapid right ventricular pacing can be expanded in neonates and infants to potentially decrease the incidence of aortic regurgitation and reintervention rates, hence avoiding high-risk surgical bail-out procedures for severe aortic regurgitation in the first year of life. Myocardial ischemia may predispose to ventricular dysrhythmias during rapid right ventricular pacing.

Epidemiology of Pediatric Cardiomyopathy in a Mediterranean Population.

BACKGROUND: Our knowledge regarding the epidemiology of pediatric cardiomyopathy is based on large national population studies reporting an annual incidence of 1 case per 100,000 children, with a higher incidence observed in infancy and among selected populations. The aim here is to document the epidemiology of pediatric cardiomyopathy in a Mediterranean population. METHODS: Children younger than 18 years of age living on the Mediterranean island of Crete, Greece, who have been evaluated since the establishment of tertiary pediatric cardiology services (2002-2022) were included in this retrospective study. RESULTS: A total of 40 children were included, corresponding to an average annual incidence of pediatric cardiomyopathy of 1.59 cases (95% CI: 1.4-2.3) and a prevalence of 26 cases per 100,000 children. In decreasing order of frequency, most cases corresponded to dilated (50%), followed by hypertrophic (42.5%), arrhythmogenic (5%), and restrictive (2.5%) cardiomyopathy. An etiology was identified in 40%, including a genetic diagnosis in 22.5%. CONCLUSIONS: The incidence of pediatric cardiomyopathy in the Mediterranean island of Crete is higher compared with that reported previously for other Caucasian populations. Further study is needed to investigate the exact prevalence and specific genetic factors associated with the epidemiology of pediatric cardiomyopathy in Mediterranean populations.

Cardiomyopathies in children: An overview.

Paediatric cardiomyopathies form a heterogeneous group of disorders characterized by structural and electrical abnormalities of the heart muscle, commonly due to a gene variant of the myocardial cell structure. Mostly inherited as a dominant or occasionally recessive trait, they might be part of a syndromic disorder of underlying metabolic or neuromuscular defects or combine early developing extracardiac abnormalities (i.e., Naxos disease). The annual incidence of 1 per 100,000 children appears higher during the first two years of life. Dilated and hypertrophic cardiomyopathy phenotypes share an incidence of 60% and 25%, respectively. Arrhythmogenic right ventricular cardiomyopathy (ARVC), restrictive cardiomyopathy, and left ventricular noncompaction are less commonly diagnosed. Adverse events such as severe heart failure, heart transplantation, or death usually appear early after the initial presentation. In ARVC patients, high-intensity aerobic exercise has been associated with worse clinical outcomes and increased penetrance in at-risk genotype-positive relatives. Acute myocarditis in children has an incidence of 1.4-2.1 cases/per 100,000 children per year, with a 6-14% mortality rate during the acute phase. A genetic defect is considered responsible for the progression to dilated cardiomyopathy phenotype. Similarly, a dilated or arrhythmogenic cardiomyopathy phenotype might emerge with an episode of acute myocarditis in childhood or adolescence. This review provides an overview of childhood cardiomyopathies focusing on clinical presentation, outcome, and pathology.

Primary Sjögren's Syndrome Presenting with Rapidly Progressive Dementia: A Case Report.

BACKGROUND: Rapidly progressive dementias (RPDs) are dementias that progress subacutely over a time period of weeks to months. Primary Sjögren's syndrome (pSS) is an autoimmune disease that can affect any organ system and may present with a wide range of clinical features that may mimic a plethora of medical conditions and, in rare cases, may manifest as RPD. We describe a unique case of pSS, in which rapidly progressive dementia (RPD) was the first disease manifestation, and the patient's radiological and electroencephalogram findings were compatible with Creutzfeldt- Jakob disease (CJD). CASE PRESENTATION: Here, we report a 58-year-old woman who presented with cognitive impairment rapidly deteriorating over the last 6 months prior to admission. Brain MRI and EEG were indicative of CJD. However, CSF 14-3-3 and tau/phospho tau ratio were within normal limits and therefore alternative diagnoses were considered. Blood tests were significant for positive antinuclear antibodies, anti-ENA, and anti-SSA and a lip biopsy was consistent with pSS. The patient was started on intravenous steroids followed by oral prednisone taper, which prevented further deterioration. CONCLUSION: This rare case expands the spectrum of neurological manifestations in pSS and highlights the importance of considering pSS in the differential diagnosis of RPDs in order to avoid misdiagnosis and provide appropriate treatment in a timely fashion.

FDXR Gene Expression after in Vivo Radiation Exposure of Pediatric Patients Undergoing Interventional Cardiology Procedures.

BACKGROUND: Ferredoxin reductase (FDXR) has already been reported as a promising biomarker for estimating radiation doses in radiotherapy. This study aimed to investigate the responsiveness of FDXR on pediatric population exposed to ionizing radiation (X-rays) during pediatric interventional cardiology (IC) procedures. PATIENTS AND METHODS: Peripheral blood was collected by venipuncture from 24 pediatric donors before and 24 hours after the IC procedure. To estimate the effective dose, demographic data and Air Kerma-Area Product (PKA) were recorded for each patient. The relative quantification (RQ) of the FDXR gene in irradiated patient blood samples compared to the non-irradiated blood samples was determined using qPCR analysis. The relative values of FDXR were log- transformed. RESULTS: The effective dose ranged from 0.002 mSv to 8.004 mSv. Over this radiation exposure range, the FDXR gene expression varied randomly with the effective dose. Up-regulation in FDXR expression was observed in 17 patients and down-regulation in 7 patients. CONCLUSIONS: Further studies in a larger cohort of pediatric patients along with the record of clinical data are needed to determine whether FDXR gene expression is an effective biomarker for radiation exposure estimation in pediatric imaging.

Trends in ablation procedures in Greece over the 2008-2018 period: Results from the Hellenic Cardiology Society Ablation Registry.

OBJECTIVE: In 2008, the radiofrequency ablation (RFA) procedures registry of the Hellenic Society of Cardiology was created. This online database allowed electrophysiologists around the country to input data for all performed ablation procedures. The aim of this study is to provide a thorough report and interpretation of the data submitted to the registry between 2008 and 2018. METHODS: In 2008, a total of 27 centers/medical teams in 24 hospitals were licensed to perform RFA in Greece. By 2018, the number had risen to 31. Each center was tasked with inserting their own data into the registry, which included patient demographics (anonymized), type of procedure and technique, complications, and outcomes. RESULTS: A total of 18587 procedures in 17900 patients were recorded in the period of 2008-2018. By 2018, slightly more than 70% of procedures were performed in 7 high-volume centers (>100 cases/year). The most common procedure since 2014 was atrial fibrillation ablation, followed by atrioventricular nodal reentry tachycardia ablation. Complication rates were low, and success rates remained high, whereas the 6-month relapse rates declined steadily. CONCLUSION: This online RFA registry has proved that ablation procedures in Greece have reached a very high standard, with results and complication rates comparable to European and American standards. Ablation procedures for atrial fibrillation are increasing constantly, with it being the most common intervention over the last 6-year period, although the absolute number of procedures still remains low, compared to other European countries.

Visible-Light Activated Titania and Its Application to Photoelectrocatalytic Hydrogen Peroxide Production.

Photoelectrochemical cells have been constructed with photoanodes based on mesoporous titania deposited on transparent electrodes and sensitized in the Visible by nanoparticulate CdS or CdS combined with CdSe. The cathode electrode was an air-breathing carbon cloth carrying nanoparticulate carbon. These cells functioned in the Photo Fuel Cell mode, i.e., without bias, simply by shining light on the photoanode. The cathode functionality was governed by a two-electron oxygen reduction, which led to formation of hydrogen peroxide. Thus, these devices were employed for photoelectrocatalytic hydrogen peroxide production. Two-compartment cells have been used, carrying different electrolytes in the photoanode and cathode compartments. Hydrogen peroxide production has been monitored by using various electrolytes in the cathode compartment. In the presence of NaHCO3, the Faradaic efficiency for hydrogen peroxide production exceeded 100% due to a catalytic effect induced by this electrolyte. Photocurrent has been generated by either a CdS/TiO2 or a CdSe/CdS/TiO2 combination, both functioning in the presence of sacrificial agents. Thus, in the first case ethanol was used as fuel, while in the second case a mixture of Na2S with Na2SO3 has been employed.

Effects of secondary biological treatment plant effluent administration, as drinking water, to rats' urogenital system in relation to cadmium and lead accumulation.

The aim of this study was to examine the effect of the secondary biological treatment plant effluent administration on the kidneys, urinary bladder, and testis of Wistar rats in relation to lead (Pb) and cadmium (Cd) accumulation, since such an effluent is used for irrigation of edible plants. Male Wistar rats, randomly assigned into 5 groups, were treated with domestic sewage effluent (DSE) for 24 months. Cadmium and lead concentrations in the DSE, rats' tissues, and urine were estimated by means of atomic spectroscopy. Lead was rapidly accumulated in high amounts in rats' kidney and to a lesser extent in the testis whereas Cd concentration was raised in all tissues examined. Deposition of Cd and Pd in the kidney of the rats resulted in profound damage over time. The results showed that long-term administration to DSE as drinking water exposes living organisms to urogenital stress related to heavy metal concentration and pH of the effluent.

Stress-impaired transcription factor expression and insulin secretion in transplanted human islets.

Type 2 diabetes is characterized by insulin resistance, hyperglycemia, and progressive ß cell dysfunction. Excess glucose and lipid impair ß cell function in islet cell lines, cultured rodent and human islets, and in vivo rodent models. Here, we examined the mechanistic consequences of glucotoxic and lipotoxic conditions on human islets in vivo and developed and/or used 3 complementary models that allowed comparison of the effects of hyperglycemic and/or insulin-resistant metabolic stress conditions on human and mouse islets, which responded quite differently to these challenges. Hyperglycemia and/or insulin resistance impaired insulin secretion only from human islets in vivo. In human grafts, chronic insulin resistance decreased antioxidant enzyme expression and increased superoxide and amyloid formation. In human islet grafts, expression of transcription factors NKX6.1 and MAFB was decreased by chronic insulin resistance, but only MAFB decreased under chronic hyperglycemia. Knockdown of NKX6.1 or MAFB expression in a human ß cell line recapitulated the insulin secretion defect seen in vivo. Contrary to rodent islet studies, neither insulin resistance nor hyperglycemia led to human ß cell proliferation or apoptosis. These results demonstrate profound differences in how excess glucose or lipid influence mouse and human insulin secretion and ß cell activity and show that reduced expression of key islet-enriched transcription factors is an important mediator of glucotoxicity and lipotoxicity.

Radiofrequency ablation procedures in Greece: initial experience and results from the national registry 2008-2010.

INTRODUCTION: In 2008 the radiofrequency ablation procedures (RFA) registry of the Hellenic Cardiological Society (HCS) was created. This is a dynamic, web-based application, which acts as the interface for storing and retrieving patients' demographic data and ablation procedures. Access to the site is permitted only to registered users. The purpose of this study is to report the results of RFA procedures performed in Greece over the 2008-2010 period. METHODS: There are 27 centers in 24 hospitals that are licensed to perform RFA in Greece. During the period 2008-2010, 3541 RFA procedures were performed in 3344 patients in 23 centers. Four centers did not contribute data at all for various reasons. It is interesting that nearly 50% of the total number of procedures were performed at 3 high volume centers (>100 cases/year). RESULTS: The most common procedure was slow pathway ablation for atrioventricular reentrant tachycardia, the second was ablation of accessory pathway related tachycardias, and the third was ablation of atrial fibrillation. Success rates were high (92.1%), the complication rate was 3% (serious complications <1%) and total relapse rate was 8.7% at six months' follow up. CONCLUSIONS: The electronic RFA registry in Greece confirmed that all RFA procedures are performed in Greece with high success and low complication rates, comparable to the European and US standards. The experience and results from the first three-year period using the registry are very interesting and encouraging, thus indicating the need for development of similar databases at the national level.

Coordinate overexpression of interferon-alpha-induced genes in systemic lupus erythematosus.

OBJECTIVE: To study the contribution of interferon-alpha (IFNalpha) and IFNgamma to the IFN gene expression signature that has been observed in microarray screens of peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: Quantitative real-time polymerase chain reaction analysis of healthy control PBMCs was used to determine the relative induction of a panel of IFN-inducible genes (IFIGs) by IFNalpha and IFNgamma. PBMCs from 77 SLE patients were compared with those from 22 disease controls and 28 healthy donors for expression of IFIGs. RESULTS: Expression of IFNalpha-inducible genes was significantly higher in SLE PBMCs than in those from disease controls or healthy donors. The level of expression of all IFIGs in PBMCs from SLE patients with IFNalpha pathway activation correlated highly with the inherent responsiveness of those genes to IFNalpha, suggesting coordinate activation of that cytokine pathway. Expression of genes preferentially induced by IFNgamma was not significantly increased in SLE PBMCs compared with control PBMCs. IFNalpha-regulated gene-inducing activity was detected in some SLE plasma samples. CONCLUSION: The coordinate activation of IFNalpha-induced genes is a characteristic of PBMCs from many SLE patients, supporting the hypothesis that IFNalpha is the predominant stimulus for IFIG expression in lupus.