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Biomedical subjects

Vassiliki Syriopoulou

Publications and source records attributed to Vassiliki Syriopoulou.

15 recordsLinked to original sources

Effects of anticonvulsant therapy on vitamin D status in children: prospective monitoring study.

Reports of hypovitaminosis D associated with anticonvulsant drugs in pediatric patients are conflicting. The effects of carbamazepine or sodium valproate on vitamin D status were evaluated prospectively in 51 ambulatory epileptic children who were followed during the first year of the study and in 25 and 6 children during the second and third year, respectively. Serum 25-hydroxyvitamin D, parathyroid hormone, calcium, and phosphorus levels were determined before and every 3 months during anticonvulsant therapy. Our subjects were grouped into four classes (0, 1, 2, and 3 consisted of the patients before and during the first, second, and third years of the treatment, respectively). The control group consisted of 80 healthy children. Comparisons between controls and patients of class 0 for the means for each season of all variables showed no significant differences. A decreasing trend in serum 25-hydroxyvitamin D (P < .03) and an increasing trend in serum parathyroid hormone (P < .04) levels were noticed in all seasons from class 0 to class 3. Twenty-five patients (49%) acquired hypovitaminosis D during the study period. The effects of seasonality on serum 25-hydroxyvitamin D, parathyroid hormone, and calcium were noticed in our patients grouped in classes 0, 2 and 3, as well as in controls. Evidence is provided that carbamazepine or sodium valproate can cause hypovitaminosis D in children.

Anticonvulsants↗

Favorable outcome of Ewing sarcoma family tumors to multiagent intensive preoperative chemotherapy: a single institution experience.

BACKGROUND: Aim of our study was to evaluate the efficacy of multiagent intensive preoperative chemotherapy in patients with Ewing sarcoma family tumors (ESFT), in order to succeed a better percentage of necrosis before surgical resection. PROCEDURE: Eighteen patients with ESFT were treated with the same multiagent intensive preoperative protocol. 5/18 patients had bone Ewings sarcoma (EWS) and 13/18 had peripheral primitive neuroectodermal tumor (PNET). None had metastases at diagnosis. Chemotherapy consisted of 5 or 6 cycles with vincristine, cisplatin, cyclophosphamide, and Adriamycin, followed by 12 cycles of vincristine, cyclophosphamide, and actinomycin-D. Five patients with EWS underwent total resection after 5-6 cycles of preoperative chemotherapy and prosthetic replacement was performed in two of them. In 3/13 patients with PNET the tumor was resected at diagnosis and in 1/13 after 5 cycles of chemotherapy, while 9/13 patients received chemotherapy only and/or radiotherapy. RESULTS: In patients with EWS, the histologic specimens of the resected tumors showed that tissue necrosis was 100% in four patients and 95% in one patient. The good histologic response reflects the effectiveness of this regimen in all ESFT. No patient had topical recurrence or developed metastatic disease during follow-up period (2-13 years, mean time 7.4 years). All patients had the scheduled cycles without delays or dose reductions. There were no major side effects of chemotherapy. CONCLUSIONS: The intensive chemotherapy schedule, comprising of 5-6 cycles preoperatively, seems to maximize the percentage of tumor necrosis, thus improving outcome. Our study implies that this combined therapy may improve the prognosis of ESFT.

Adolescent↗

Mother to child transmission of hepatitis C virus: rate of infection and risk factors.

To determine the rate of mother-to-child transmission of hepatitis C virus (HCV) and identify risk factors associated with HCV transmission we prospectively studied 86 infants born to anti-HCV positive mothers. HCV infection was verified in all mothers before delivery and their HCV viral load was measured at or near delivery using reverse transcription polymerase reaction. For HCV genotyping the INNO-LiPA II probe assay was used. All mothers were tested for HIV infection. Possible risk factors for vertical transmission were recorded. The children were followed up for a minimum of 18 months for evidence of HCV infection, as determined by persistent HCV antibodies, or detection of HCV-RNA. Vertical transmission was restricted to infants born to viraemic mothers and the rate was 3.6% (95% CI 0.004-0.123). The HIV-infected mothers and those using drugs intravenously were more likely to transmit HCV to their children. The infected children had the same genotype as their mothers. Although the HCV RNA titre was higher in mothers who transmitted the virus than in those who did not, the viral load had borderline significance (p=0.08). Viral transmission was not influenced by mother's age, mode of delivery, genotype or type of feeding. Mother-to-child transmission of hepatitis C virus is uncommon and restricted to infants born to HCV viraemic mothers. Active drug use and HIV coinfection increase the risk for HCV vertical transmission.

Adult↗

Could intensified treatment in childhood acute lymphoblastic leukemia improve outcome independently of risk factors?

PURPOSE: Many risk-directed therapeutic protocols have been proposed in acute lymphoblastic leukemia (ALL). However, the relapse rates remain high. The effectiveness of each protocol depends on how quickly the clearance of blast cells is achieved. In an attempt to improve survival, by minimizing treatment toxicity and relapse rate, different therapeutic protocols were used every 3 yr in our Unit. PATIENTS AND METHODS: During 1991-2000, 132 children with ALL were diagnosed in our Unit. Modified and intensified NY II and BFM protocols, in three consecutive periods [(Hematology/Oncology Pediatric Department of the University of Athens) HOPDA-91, HOPDA-94, HOPDA-97] were used. RESULTS: At a median follow-up time of 96 months, the 8-year overall survival (OS) was 88% +/- 3%, whereas the event-free survival (EFS) was 85% +/- 3%. There was a significant increase of the 5-year EFS of the high-risk (HR) group through time (65% in HOPDA-91 vs. 80% in HOPDA-97), whereas EFS of the low risk (LR) group in HOPDA-97 was 96%. Five cases relapsed (3.8%), four of which underwent successful bone marrow transplantation. Fifteen children died (13 diagnosed by 1996, two in the last 4 yr). CONCLUSION: Modification of the protocols significantly improved survival in both HR and LR groups. The intensified regimen in the LR group did not increase the adverse toxic events, but on the contrary was extremely effective.

Adolescent↗

Sustained response to interferon alpha-2a in thalassemic patients with chronic hepatitis C. A prospective 8-year follow-up study.

Eighty-nine thalassemic patients with chronic hepatitis C were treated with interferon alpha-2a for 12 months and followed up for 8 years. Interferon induced sustained virologic and biochemical response in 45% of participants and histologic improvement in 50% of patients who had paired liver biopsies. Splenectomy was the only independent predictor of an unfavorable outcome.

Adolescent↗

Serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae causing invasive infections and acute otitis media in children.

UNLABELLED: A prospective study was conducted to determine the serotypes and antibiotic resistance patterns of pneumococcal isolates from children with invasive pneumococcal disease (IPD) and acute otitis media (AOM). From October 2001 to May 2002, 65 children with IPD (28 bacteraemic pneumonia, 24 bacteraemia without focus, 7 meningitis, 6 other infections) and 78 with AOM were identified. The most common serotypes causing IPD were 14 (32.3%), 6B (20.0%), 1 (18.5%) and 19F (7.7%) whereas the predominant serotypes causing AOM were 19F (35.9%), 14 (16.7%) and 23F (9.1%). Sixty-nine percent of IPD and 70.5% of AOM were caused by vaccine serotypes. The vaccine serotypes were more commonly encountered in meningitis cases and in children younger than 2 years of age. Intermediate resistance to penicillin was observed in 6 of 65 (9.2%) IPD isolates, one of which was intermediately resistant to cefotaxime (1.6%), whereas none exhibited high-level resistance to penicillin or other beta-lactam antibiotics. A higher proportion of antimicrobial resistance was noted in AOM isolates; 29 of 78 (37.4%) exhibited intermediate resistance and 8 (10.2%) high level resistance to penicillin, four of which had intermediate resistance to cefotaxime. Significant resistance was also noted to erythromycin; 38.5% of IPD and 48.7% of AOM isolates were resistant. Multidrug resistance was observed in one IPD and in eight AOM isolates. CONCLUSION: these findings have implications in the potential use of 7-valent conjugate vaccine in our region.

Acute Disease↗

Salmonella bacteraemia in a tertiary children's hospital.

A retrospective study was conducted between July 1990 and July 2002 to investigate the epidemiology, clinical characteristics, and the outcome of Salmonella bacteraemia in children. A total of 148 episodes of bacteraemia were identified in 144 children. The annual incidence ranged from 1.6 to 8.3 cases per 100,000 children < or = 14 y of age, and higher numbers of cases occurred in summer than in winter months. In 22 children the bacteraemia was caused by S. typhi and in 122 by S. non-typhi. S. enteritidis was the most common serotype isolated. Resistance to ampicillin was exhibited by 28.5% of Salmonella isolates, whereas all S. typhi isolates were susceptible to commonly used antibiotics. The mean age was 40.3 months (range 50 d to 14 y). Children with S. typhi bacteraemia were significantly older than children with S. non-typhi bacteraemia (7.8 vs 2.4 y, p < 0.01). 11 children were immunosuppressed. The immunosuppressed children had longer duration of fever, longer hospitalization stay, and higher relapse rates compared to normal children (p < 0.05). Four children developed complications and 1 died. Although the incidence of S. typhi bacteraemia is decreasing, the non-typhi species continue to cause significant morbidity in our geographical region.

Adolescent↗

Oligonucleotide-functionalized gold nanoparticles as probes in a dry-reagent strip biosensor for DNA analysis by hybridization.

The highly specific molecular recognition properties of oligonucleotides are combined with the unique optical properties of gold nanoparticles for the development of a dry-reagent strip-type biosensor that enables visual detection of double stranded DNA within minutes. The assay does not require instrumentation and avoids the multiple incubation and washing steps performed in most current assays. Gold nanoparticle reporters with oligo(dT) attached to their surface form an integral part of the strip. Biotinylated PCR products (233 bp or 495 bp) are hybridized (5 min) with a poly(dA)-tailed oligo and applied on the strip, which is then immersed in the appropriate buffer. As the buffer migrates upward, it rehydrates the nanoparticles that are linked to the target DNA through poly(dA)/(dT) hybridization. Capture of the hybrids by immobilized streptavidin in the test zone of the strip generates a characteristic red band. A second red band is formed, by hybridization, in the control zone of the strip to indicate proper test performance. The sensor offers at least 8 times higher detectability than ethidium bromide staining of agarose gels and provides confirmation of the amplified fragments. Quantitative data are obtained by densitometric analysis of the bands. As low as 2 fmol of amplified DNA were detectable by the strip sensor. Also, 500 copies of prostate-specific antigen cDNA were detected by combining PCR and the strip sensor. The sensor was used successfully for detection of hepatitis C virus in plasma samples from 20 patients. The strip detected 16 out of 16 positive samples and gave no signal for 4 samples that were negative for the virus. To our knowledge, this is the first dry-reagent system that makes use of oligonucleotide-conjugated gold nanoparticles as probes.

Biosensing Techniques↗

Two doses of a lipid formulation of amphotericin B for the treatment of Mediterranean visceral leishmaniasis.

To evaluate the efficacy of a short course of a lipid formulation of amphotericin B (L-AmB) for the treatment of Mediterranean visceral leishmaniasis (VL), an open prospective study was conducted. Forty-one children with parasitologically confirmed leishmaniasis received L-AmB, 10 mg/kg daily for 2 days. The comparison groups were 30 children who, in a previous study, were treated with L-AmB, 4 mg/kg daily for 5 days, and 52 children who were treated with meglumine antimoniate. At 6 months after completion of treatment, overall treatment success was noted for 40 of 41 children treated with 2 doses of L-AmB, 27 of 30 children treated with 5 doses of L-AmB, and 47 of 52 children treated with meglumine antimoniate. Abatement of fever, reduction in spleen size, and correction of laboratory parameters occurred more quickly among the children who received 2 doses of L-AmB than among the comparison groups, and the total estimated cost of the 2-dose regimen was also lower than that of the other regimens. Two doses of L-AmB, 10 mg/kg each, is cost-effective therapy for Mediterranean VL in children.

Amphotericin B↗

Structures, locations, and transfer frequencies of genetic elements conferring high-level gentamicin resistance in Enterococcus faecalis isolates in Greece.

The elements conferring high-level gentamicin resistance in 64 clinical isolates of Enterococcus faecalis were characterized by PCR and by restriction enzyme hybridization analysis of genomic and plasmid DNA. There was a strong association between gentamicin resistance and the aac(6')-aph(2") gene carried on IS256-based elements with different structures, locations, and transfer characteristics.

Acetyltransferases↗

Multinational study of pneumococcal serotypes causing acute otitis media in children.

BACKGROUND: Streptococcus pneumoniae is a major cause of acute otitis media (AOM) in young children. More than 90 immunologically distinct pneumococcal serotypes have been identified, but limited information is available regarding their relative importance in AOM. METHODS: We analyzed nine existing datasets comprising pneumococcal isolates from middle ear fluid samples collected from 1994 through 2000 from 3,232 children with AOM from Finland, France, Greece, Israel, several East European countries, the US and Argentina. We examined the distribution of pneumococcal serotypes in relation to several demographic and epidemiologic variables, including gender, age, antibiotic resistance and source of culture material. RESULTS: The major serotypes identified included 19F and 23F, each comprising 13 to 25% of pneumococcal middle ear fluid isolates in most datasets; 14 and 6B, comprising 6 to 18%; whereas 6A, 19A and 9V each comprised 5 to 10%. Despite differences in location, study design and antibiotic susceptibility, each major serotype was prominent in most age groups of each dataset. Serotypes represented in the 7-valent pneumococcal conjugate vaccine (PCV-7, 4, 6B, 9V, 14, 18C, 19F, 23F) accounted for 60 to 70% of all pneumococcal isolates in the 6- to 59-month age range, but only 40 to 50% of isolates in children <6 or >/=60 months old. Serotype 3 and, in certain datasets, serotypes 1 and 5, were more important in the <6- and >/=60-month age groups. In each age group vaccine-related serotypes (mainly 6A and 19A) comprised an additional 10 to 15% of all pneumococcal isolates. Four serotypes (23F, 19F, 14 and 6B) accounted for 83% of all penicillin-resistant observations. CONCLUSIONS: This analysis of several geographically diverse datasets indicates that a limited number of serotypes, largely represented in PCV-7, accounted for the majority of episodes of pneumococcal AOM in children between 6 and 59 months of age. Certain serotypes appeared to be relatively more significant in children <6 months or >59 months of age.

Age Factors↗