Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Antigoni Siamopoulou is active.

Publication


Featured researches published by Antigoni Siamopoulou.


Arthritis & Rheumatism | 1999

Association of the inflammatory state in active juvenile rheumatoid arthritis with hypo–high‐density lipoproteinemia and reduced lipoprotein‐associated platelet‐activating factor acetylhydrolase activity

Alexandros D. Tselepis; Moses Elisaf; Sotiris Besis; Sonia-Athena P. Karabina; M. John Chapman; Antigoni Siamopoulou

OBJECTIVE To investigate the relationship between the quantitative and qualitative abnormalities of apolipoprotein B (Apo B)- and Apo A-I-containing lipoproteins and between lipoprotein-associated platelet-activating factor acetylhydrolase (PAF-AH) activity in patients with juvenile rheumatoid arthritis (JRA) as a function of the inflammatory state. METHODS Twenty-six JRA patients and 22 age- and sex-matched control subjects with normal lipid levels participated in the study. Fourteen patients had active disease, and 12 had inactive disease. Plasma lipoproteins were fractionated by gradient ultracentrifugation into 9 subfractions, and their chemical composition and mass were determined. The PAF-AH activity associated with lipoprotein subfractions and the activity in plasma were also measured. RESULTS Patients with active JRA had significantly lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol levels as compared with controls, due to the decrease in the mass of both the HDL2 and HDL3 subfractions. Patients with active JRA also had higher plasma triglyceride levels, mainly due to the higher triglyceride content of the very low-density lipoprotein plus the intermediate-density lipoprotein subfraction. The plasma PAF-AH activity in patients with active JRA was lower than that in controls, mainly due to the decrease in PAF-AH activity associated with the intermediate and dense low-density lipoprotein subclasses. The lipid abnormalities and the reduction in plasma PAF-AH activity were significantly correlated with plasma C-reactive protein levels and were not observed in patients with inactive JRA. CONCLUSION This is the first study to show that patients with active JRA exhibit low levels of HDL2 and HDL3 and are deficient in plasma PAF-AH activity. These alterations suggest that active JRA is associated with partial loss of the antiinflammatory activity of plasma Apo B- and Apo A-I-containing lipoproteins.


The Journal of Urology | 2006

Duplex Collecting System Diagnosed During the First 6 Years of Life After a First Urinary Tract Infection: A Study of 63 Children

Ekaterini Siomou; Frederica Papadopoulou; Konstantinos Kollios; Andreas Photopoulos; Eleni Evagelidou; P.A. Androulakakis; Antigoni Siamopoulou

PURPOSE We determined the prevalence, anatomical variants and coexisting complications of duplex collecting systems in children with a history of UTI. Additionally, we compared the prevalence and severity of the coexisting anomalies with those found in single systems. MATERIALS AND METHODS We reviewed the records of children younger than 6 years who were evaluated following a first UTI during a 9-year period to identify those with duplex systems. Children without duplication anomalies comprised the control group. RESULTS Of 774 evaluated children 63 (8%), more commonly females than males, had duplex systems. CDS were as common as IDS. VUR was the most commonly associated anomaly, with a higher prevalence in CDS (66%) and IDS (47%) compared to single systems (26%, p <0.0001 and p = 0.007, respectively). Ectopic ureterocele, which was the second most common associated anomaly, was found in 20% of the CDS but in none of the IDS or single systems. The occurrence of renal scarring was similar among CDS, IDS (13%) and single systems (10%). Poorly functioning pole moieties occurred more often in CDS (40%) compared to IDS (4%, p = 0.003), and were observed in none of the single systems. The resolution rate of reflux tended to be higher in IDS compared to CDS. CONCLUSIONS CDS were a common finding among children with UTI who had duplication anomalies. Although CDS and IDS were accompanied by VUR more often than were single systems, CDS were associated more often with severe VUR, other serious complications and poor renal function.


Pediatrics | 2009

Implications of 99mTc-DMSA Scintigraphy Performed During Urinary Tract Infection in Neonates

Ekaterini Siomou; Vasileios Giapros; Andreas Fotopoulos; Maria Âasioti; Frederica Papadopoulou; Anastasios Serbis; Antigoni Siamopoulou; Styliani Andronikou

OBJECTIVE: To evaluate prospectively whether normal scintigraphic results during urinary tract infections (UTIs) in neonates were predictive of the absence of dilating vesicoureteral reflux (VUR) (grade ≥III) and permanent renal damage (PRD). METHODS: Term neonates with a first symptomatic, community-acquired UTI participated in the study. Urinary tract ultrasonography and technetium-99m-labeled dimercaptosuccinic acid (99mTc-DMSA) scintigraphy were performed within 72 hours after diagnosis and voiding cystourethrography within 1 to 2 months. DMSA scintigraphy, to determine the development of PRD, was repeated 6 months after UTI. RESULTS: Seventy-two neonates (144 renal units) were enrolled. Acute pyelonephritis was diagnosed through early DMSA scintigraphy in 19% of renal units, VUR in 22%, and grade ≥III VUR in 13%. The majority (71%) of renal units with grade ≥III VUR had normal early DMSA scintigraphic results. The sensitivity and specificity of abnormal early DMSA scintigraphic results to predict grade ≥III VUR were 29% (95% confidence interval: 11%–55%) and 82% (95% confidence interval: 74%–88%), respectively. PRD was found in 7% of renal units, all of which had abnormal early DMSA scintigraphic results. PRD was significantly more frequent among renal units with grade ≥III VUR than among nonrefluxing renal units (P < .05). CONCLUSIONS: Normal early DMSA scintigraphic results for neonates with symptomatic UTIs were helpful in ruling out later development of PRD but were not predictive of the absence of dilating VUR. To rule out dilating VUR, voiding cystourethrography may be required.


Pediatrics | 2007

Provocation of Neurocardiogenic Syncope During Head-up Tilt Testing in Children: Comparison Between Isoproterenol and Nitroglycerin

Antonios P. Vlahos; Meropi Tzoufi; Christos S. Katsouras; Theodora Barka; Irene Sionti; Lampros K. Michalis; Antigoni Siamopoulou; Theofilos M. Kolettis

OBJECTIVE. Although nitroglycerin- and isoproterenol-augmented tilt tests are of equal value in the diagnosis of neurocardiogenic syncope in adults, no data exist in children. We compared the sensitivity and specificity of the 2 tests in a pediatric population. PATITENS AND METHODS. We studied 85 patients (33 boys; mean age: 11.6 ± 2.9 years). Of them, 56 had a diagnostic history of neurocardiogenic syncope, whereas 29 served as controls. After a negative passive phase, they were randomly assigned to either intravenous isoproterenol or sublingual nitroglycerin, and tilt was continued for 20 minutes. RESULTS. Sensitivity was 0.78 for the isoproterenol test and 0.79 for the nitroglycerin test, but specificity was significantly higher for isoproterenol test compared with nitroglycerin test. In patients with a positive test, the duration of the recovery period was significantly longer after nitroglycerin (8.4 ± 2.7 minutes) than after isoproterenol (5.1 ± 1.6 minutes). CONCLUSIONS. Nitroglycerin- and isoproterenol-augmented tilt tests are associated with equal sensitivity in the diagnosis of neurocardiogenic syncope in children and adolescents. However, nitroglycerin results in more false-positive tests and produces more prolonged vasovagal symptoms. Our data do not support the routine use of nitroglycerin in the evaluation of syncope in this age group.


Arthritis Care and Research | 2011

Changes in vascular function and structure in juvenile idiopathic arthritis

Antonios P. Vlahos; Paraskevi Theocharis; Aris Bechlioulis; Katerina K. Naka; Konstantinos Vakalis; Nikolaos D. Papamichael; Sapfo Alfantaki; Konstantina Gartzonika; Anestis Mavridis; Lampros K. Michalis; Antigoni Siamopoulou

Chronic inflammatory diseases in adults have been associated with increased cardiovascular risk and impaired vascular function. We aimed to assess the presence of early vascular dysfunction in patients with juvenile idiopathic arthritis (JIA) and investigate the role of inherent inflammatory process of JIA in vascular health.


Calcified Tissue International | 2001

Effects of Intranasal Salmon Calcitonin in Juvenile Idiopathic Arthritis: An Observational Study

Antigoni Siamopoulou; Anna Challa; P. Kapoglou; V. Cholevas; Anestis Mavridis; Peter D. Lapatsanis

The aim of this study was to follow the changes in bone mineral density (BMD) and biochemical markers of bone turnover in 10 children (7.5-17.5 years of age) with severe juvenile idiopathic arthritis (JIA), during a 3-year therapy with salmon calcitonin (100 IU/day 2 months on and 2 off for a year and 200 IU/day for 2 years) and calcium (500 mg/day). All patients were functional classes III and IV and were measured at yearly intervals with a dual photon absorptiometer at the lumbar spine. The changes observed were 7.2-9.5% per year for BMD and 2.0-6.0% for volumetric bone mineral density (BMDvol). The bone resorption markers showed significant decreases after a years treatment (Pyr/Cr from 175+/-15 to 108+/-15 nm/mm, P < 0.001, Pyr-D/Cr from 24.3+/-3.5 to 13.3+/-1.9 nm/mm, P < 0.05, and OHPr/Cr from 57.4+/-11 to 35.1+/-8.4 microg/mg) and smaller changes thereafter. No significant changes were observed in the bone formation markers of osteocalcin and alkaline phosphatase. Serum iPTH, the vitamin D metabolites, and calcium concentrations fluctuated within normal, while calcium excretion increased from 0.3+/-0.1 to 1.9+/-0.4 mg/kg/24 hours, P < 0.001. In conclusion, the present study, despite its limitations of not being placebo controlled, shows possible beneficial effects of intranasal calcitonin on bone resorption and pain relief in JIA patients.


Calcified Tissue International | 2003

Biochemical markers of bone metabolism in infants and children under intravenous corticosteroid therapy

Ekaterini Siomou; Anna Challa; Meropi Tzoufi; Zoe L. Papadopoulou; Pd Lapatsanis; Antigoni Siamopoulou

The short-term effects of corticosteroids (CS) administered intravenously (IV) on biochemical parameters of bone metabolism were followed in infants and children. Forty-nine patients from 2 months to 10 years of age, admitted to Pediatrics Department for bronchiolitis, viral-associated wheezing and croup, were treated with IV hydrocortisone or methylprednisolone (10 or 2 mg/Kg/day, respectively) for 3 days. Blood and fasting urine were collected on admission (day 1), 2 days later (day 3) and 12 days after the end of therapy (day 15). Fifty-one children of similar age and gender without respiratory problems or bone diseases were used as controls. On day 3, suppression of the bone formation markers osteocalcin (OC) (P < 0.001) and total alkaline phosphatase (ALP) (P < 0.05) was observed, but not of the bone resorption markers of hydroxyproline, pyridinoline and calcium excretion (UHyp/UCr, UPYD/UCr and UDPD/UCr, UCa/UCr). Significant decreases were indicated in serum phosphate (Pi) and the maximum renal tubular Pi reabsorption (TmP/GFR) compared to basal (P < 0.001). No significant changes were noticed in the circulating levels of calcium (Ca), parathyroid hormone (iPTH), 25OHD, 24,25(OH)2D, 1,25(OH)2D, the insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3). Two weeks after therapy, the increase of OC to higher than basal (P < 0.01) indicated a probable activation of the osteoblasts. Serum Pi and the TmP/GFR index values that had significantly decreased by day 3 returned to pretreatment levels by day 15. When assessing the effects of the CS in relation to age, no changes were detected in the levels of OC and total ALP in the <12-month-old children, but a fall of OC was observed in the >1-year-old group (P < 0.001). In contrast to the OC, the effects on serum and renal tubular reabsorption of phosphate were similar for both groups. In conclusion, short-term IV administered CS led to significant but reversible inhibition of bone formation markers, especially detectable in the >1-year-old children, without affecting the bone resorption ones. The adverse effects on phosphate metabolism were also significant, but temporal and irrespective of age.


Pediatric Rheumatology | 2008

14.3 Early cardiovascular risk assessment in patients with juvenile idiopathic arthritis

Antonios P. Vlahos; S Alfantaki; A Bechlioulis; K Vakalis; Lampros K. Michalis; Antigoni Siamopoulou

Background Inflammation has emerged as an important factor that contributes to the development of atherosclerosis and is associated with increased cardiovascular risk. Juvenile idiopathic arthritis (JIA) is a chronic inflammatory condition with its origin in childhood. Its adult form, rheumatoid arthritis, has been associated with an excess of cardiovascular disease even after adjustment for traditional risk factors.


Pediatric Nephrology | 2014

Arterial hypertension during treatment with triptorelin in a child with Williams–Beuren syndrome

Ekaterini Siomou; Chrysoula Kosmeri; Maria Pavlou; Antonios P. Vlahos; Maria I. Argyropoulou; Antigoni Siamopoulou

BackgroundArterial hypertension (AHT) is a common finding in children with Williams–Beuren syndrome (WBS). Although cardiovascular and renal abnormalities can explain the AHT in some patients with WBS, its etiology is not fully understood and most cases are considered idiopathic.Case-diagnosis/treatmentThe case is reported of a 10-year-old girl with WBS who developed severe AHT during treatment with triptorelin, a long-lasting gonadotropin-releasing hormone (GnRH) analog, administered because of early normal puberty. Comprehensive diagnostic studies ruled out other known causes of AHT associated with WBS. After discontinuation of triptorelin, the blood pressure remained within the normal range for her age and height with no antihypertensive treatment on long-term follow-up. To the best of the authors’ knowledge, this is the first report of AHT associated with triptorelin administration in a child with WBS.ConclusionsClinicians should be aware of the possibility, although rare, of AHT developing during triptorelin administration in childhood, specifically in patients at increased risk of AHT, such as those with WBS.


Pediatric Research | 2007

Angiotensin II type 2 receptor gene polymorphism in caucasian children with a wide spectrum of congenital anomalies of the kidney and urinary tract

Ekaterini Siomou; Ioanna Bouba; Konstantinos Kollios; Frederica Papadopoulou; Maria Syrrou; Ioannis Georgiou; Antigoni Siamopoulou

The A-1332G transition of the angiotensin II type 2 receptor (AT2R) gene was found to occur more often in males with ureteropelvic (UPJO) or ureterovesical junction obstruction (UVJO). However, other studies have shown controversial results. Τhe frequency of this polymorphism was investigated in 275 Caucasian children (153 boys, 122 girls) with a wide spectrum of congenital anomalies both of upper (165) and lower (110) urinary tract system and in 200 controls (100 boys, 100 girls). Among the included malformations, renal agenesis and duplex collecting system (DCS) were studied for the first time. The frequency of the G allele did not differ among patients (193 of 397 total alleles, 48.6%) and controls (146 of 300, 48.7%). No significant difference was also found in the frequency of the G allele in subgroups of congenital uropathies compared with controls. When analysis was performed in males and females separately, no significant difference was found in the frequency of the G allele in male (45.1%) or female (50.8%) patients compared with male (57.0%) or female (44.5%) controls. Our data indicate that the AT2R gene A-1332G transition is not associated with the development of human congenital uropathies and further investigations should be carried out to unravel their etiology.

Collaboration


Dive into the Antigoni Siamopoulou's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Anna Challa

University of Ioannina

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge