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Biomedical subjects

A Antoniadis

Publications and source records attributed to A Antoniadis.

At least 19 recordsLinked to original sources

Greek measles epidemic strain, 2005-2006.

The purpose of this work was the molecular study of the virus strain that caused the last measles outbreak in Greece. Twenty-four saliva specimens were obtained from selected patients serologically confirmed as measles cases between December 2005 and March 2006. Measles virus (MV) detection was performed by a nested RT-PCR. The 447-bp segment of the N gene of these MV strains was used for genotyping. The N gene sequences of the Greek MV strains were identical to each other, therefore a phylogenetic tree was constructed using one representative MV (ThesGRE/06). Our data show that the MV strain which caused the 2005-2006 outbreak in Greece belongs to genotype D6, and differs by 0.68% from the New Jersey D6 strain and by 5.5% from the MV vaccine strain Edmonston B (U03656) belonging to genotype A.

Adult↗

Efficacy and safety of enteric-coated mycophenolate sodium (myfortic) in de novo renal transplant recipients: results of a 12-month multicenter, open-label, prospective study.

Enteric-coated mycophenolate sodium (EC-MPS) has been developed as an alternative formulation of mycophenolate acid aiming for improved gastrointestinal (GI) tolerability. This 12-month, open-label, multicenter, prospective study investigated the efficacy and tolerability of EC-MPS (720 mg twice a day) given in combination with cyclosporine microemulsion (CsA-ME) in de novo renal transplant recipients (n=140). The efficacy evaluation was the incidence of treatment failure (defined as biopsy-proven acute rejection [BPAR], graft loss, or death) after 6 and 12 months of treatment. The incidences of treatment failure, BPAR, and graft loss were comparable at 6 and 12 months (18.6% vs 22.1%, 15.7% vs 19.3%, and 1.4% vs 2.1%, respectively). Renal function at 6 and 12 months (creatinine clearance) was 60.6+/-19.8 mL/min and 63.2+/-27.1 mL/min, respectively. EC-MPS was generally well tolerated; 95.9% of the reported GI adverse events (AEs) were rated as mild or moderate. The rate of EC-MPS dose reduction was 26.4%; 4.3% were due to GI AEs. The rate of EC-MPS dose interruption was 10%; 2.1% were due to GI AEs. In summary, EC-MPS given in combination with CsA-ME demonstrates good efficacy and tolerability in de novo renal transplant recipients.

Adult↗

Sandfly fever virus outbreak in Cyprus.

A major outbreak of febrile syndrome occurred during 2002 among the Greek Army forces in Cyprus. Serological and molecular investigations revealed that the causative agent was a Sicilian-like phlebovirus. A virus strain was isolated from a blood sample taken on the first day of the disease. Phylogenetic analysis of partial L RNA segment sequences revealed that the strain from Cyprus differed from sandfly Sicilian virus by 6.7% at the nucleotide level.

Adult↗

Genetic variation of coxsackie virus B5 strains associated with aseptic meningitis in Greece.

In order to explore the genetic relationships among coxsackie virus B5 strains in Greece, the nucleotide sequences of the partial VP1 gene in strains isolated from aseptic cases of meningitis were determined and compared with those of strains isolated from other countries. Phylogenetic analysis showed a high degree of divergence (25%) among Greek strains isolated in different years, which clustered with high bootstrap values in a different subgroup of viruses, suggesting that enterovirus types vary with time rather than geographical distribution. A non-synonymous mutation present in the strains of this study was not observed in other coxsackie virus B5 strains.

Adolescent↗

Genetic characterization of the M RNA segment of a Balkan Crimean-Congo hemorrhagic fever virus strain.

Crimean-Congo hemorrhagic fever (CCHF) virus causes one of the most severe diseases in humans, with a mortality rate of up to 30%. It is transmitted to humans by the bite of hard ticks or by contact with blood or tissues from human patients or infected livestock. Balkan Peninsula is an endemic region of the disease, and sporadic cases or even outbreaks are observed every year. The M RNA segment encodes for the glycoprotein precursor of two surface glycoproteins Gn and Gc. Up to now complete M RNA CCHF virus sequences have been published from strains isolated in Nigeria, China, Pakistan, Tajikistan, and Russia. In the present study, the genetic characterization of the complete nucleotide sequence of the M RNA segment of a Balkan CCHF virus strain, Kosovo/9553/2001, isolated in summer of 2001 from a human fatal case in Kosovo is reported. This is the first published complete M nucleotide sequence of a CCHF virus strain isolated in Balkans. It was found that the Balkan strain is similar to the Russian strain, both strains differing from all other completely sequenced CCHF virus strains by approximately 22% at the nucleotide level forming an independent clade in the phylogenetic tree.

DNA, Complementary↗

A seroprevalence study of poliovirus antibody in the population of northern Greece.

This study assessed immunity to poliomyelitis in a representative sample of 1064 persons living in northern Greece. Antibody prevalences in the individuals tested were 91.1% (95% confidence interval (CI): 89.4-92.8), 92.1% (95% CI: 90.5-93.7) and 83.1% (95% CI: 80.8-85.4) for poliovirus types 1, 2 and 3, respectively. For poliovirus type 3, a gap in immunity was found in individuals aged 10-29 years. Re-vaccination of adolescents living in northern Greece is suggested to ensure herd immunity and to minimise the risk of importation of wild poliovirus from endemic countries.

Adolescent↗

Seroprevalence of Toxoplasma gondii in northern Greece during the last 20 years.

The seroprevalence of Toxoplasma gondii in the northern Greek population was determined in 1984, 1994 and 2004, and changes during this period were investigated. In total, 1014, 812 and 958 sera from individuals aged 1 day to 70 years were examined in 1984, 1994 and 2004, respectively, for IgG and IgM anti-Toxoplasma antibodies with the standard immunofluorescence assay (IFA) and microparticle enzyme immunoassay (MEIA). In individuals positive for IgM-specific antibodies, primary infection with Toxoplasma was diagnosed on the basis of the Toxoplasma serological profile (IFA, MEIA, conventional IgM and IgA ELISAs, immunosorbent agglutination assay and IgG avidity test). The prevalence of IgG-specific antibodies in the general population was 37%, 29.9% and 24.1% in 1984, 1994 and 2004, respectively, and was 35.6%, 25.6% and 20%, respectively, in women of reproductive age (15-39 years). The incidence of Toxoplasma infection, based on cases of primary infection and the annual seroconversion rate for the general population, was estimated to be 1.25% and 1.1% in 1984, 1.05% and 0.93% in 1994, and 0.85% and 0.8% in 2004. The significant decline in prevalence, and the shift towards an older age group, observed during this period could be explained by the improved socio-economic situation. The high (80%) proportion of women of reproductive age susceptible to Toxoplasma infection, with an estimated 90-200 neonates infected in utero annually, seems to present a potential risk to public health. Education of the public and prophylactic measures may become increasingly important.

Adolescent↗

Biological detection of low radiation doses by combining results of two microarray analysis methods.

The accurate determination of the biological effects of low doses of pollutants is a major public health challenge. DNA microarrays are a powerful tool for investigating small intracellular changes. However, the inherent low reliability of this technique, the small number of replicates and the lack of suitable statistical methods for the analysis of such a large number of attributes (genes) impair accurate data interpretation. To overcome this problem, we combined results of two independent analysis methods (ANOVA and RELIEF). We applied this analysis protocol to compare gene expression patterns in Saccharomyces cerevisiae growing in the absence and continuous presence of varying low doses of radiation. Global distribution analysis highlights the importance of mitochondrial membrane functions in the response. We demonstrate that microarrays detect cellular changes induced by irradiation at doses that are 1000-fold lower than the minimal dose associated with mutagenic effects.

Analysis of Variance↗

Effective dimension reduction methods for tumor classification using gene expression data.

MOTIVATION: One particular application of microarray data, is to uncover the molecular variation among cancers. One feature of microarray studies is the fact that the number n of samples collected is relatively small compared to the number p of genes per sample which are usually in the thousands. In statistical terms this very large number of predictors compared to a small number of samples or observations makes the classification problem difficult. An efficient way to solve this problem is by using dimension reduction statistical techniques in conjunction with nonparametric discriminant procedures. RESULTS: We view the classification problem as a regression problem with few observations and many predictor variables. We use an adaptive dimension reduction method for generalized semi-parametric regression models that allows us to solve the 'curse of dimensionality problem' arising in the context of expression data. The predictive performance of the resulting classification rule is illustrated on two well know data sets in the microarray literature: the leukemia data that is known to contain classes that are easy 'separable' and the colon data set.

Algorithms↗

A case of pleurisy associated with antibodies to Rickettsia conorii.

Rickettsia conorii is endemic in Mediterranean area. We describe an unusual sace of R. Conorii infection, which concerns a farmer with clinical, radiological and cytological findings of pleurisy without evidence of malignancy. An elevated antibody titre for R. Conorii was observed, using an indirect immunofluorescent antibody test. After treatment with Doxycycline, the patient presented a significant improvement of his clinical and radiological image and a four-fold decrease of the antibody titre for R. conorii.

Adult↗

Infrequent detection of acquired metallo-beta-lactamases among carbapenem-resistant Pseudomonas isolates in a Greek hospital.

OBJECTIVE: To study the possible distribution of metallo-beta-lactamases among nosocomial Pseudomonas isolates in a Greek hospital with a recent high prevalence of carbapenem-resistant Pseudomonas isolates. METHODS: All carbapenem-resistant (imipenem- and/or meropenem-resistant) (MICs > 8 mg/L) Pseudomonas non-replicate isolates recovered from clinical infections in the Microbiology Laboratory of Saint Demetrios Hospital, Thessaloniki, Greece, from April 1998 to November 2000 were studied for the presence of metallo-beta-lactamases. They were tested by a disk diffusion test, PCR analysis, and nucleotide sequencing. DNA fingerprints were obtained by pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA. RESULTS: In total, 24 carbapenem-resistant isolates (23 P. aeruginosa and one P. putida) were recovered. The serotypes observed among the P. aeruginosa isolates were, in order of decreasing frequency, O:11 (52%), O:3 and O:12 (17% each), and O:6 (13%). PFGE grouped 17 of the P. aeruginosa isolates into four clusters, each containing from two to seven isolates, while the remaining isolates exhibited unique genotypes. blaVIM-2 was detected in the P. putida isolate and a P. aeruginosa serotype O:3 isolate. The latter strain was genotypically distinct from other contemporaneous or older carbapenem-resistant P. aeruginosa Greek isolates. CONCLUSION: These findings suggest that, although the prevalence of metallo-beta-lactamases is low, the integron-associated blaVIM genes can spread to P. aeruginosa serotypes that have not been previously associated with carbapenem resistance in our region, as well as to other pseudomonal species.

Carbapenems↗

Occurrence of Bartonella henselae and Bartonella quintana in a healthy Greek population.

The purpose of this study was to determine the prevalence of IgM and IgG antibodies against Bartonella henselae and B. quintana in a healthy Greek population using a commercially available immunofluorescent test (Focus test). Five hundred healthy individuals were divided by sex into four age groups and three groups according to contact with cats. IgM antibodies were not detected in any of the subjects examined, while 99 (19.8%) and 75 (15%) were IgG seropositive to B. henselae and to B. quintana, respectively. No statistical difference in the seropositivity was observed among these groups. The IgG antibody titers ranged from 1/64 to 1/256 for B. henselae and from 1/64 to 1/512 for B. quintana. A high percentage (12.4%) of cross-reactivity between the two species was observed. Our data show that the prevalence of both Bartonella species in Greece is high. However, low IgG antibody levels are not sufficient evidence of active infection.

Adolescent↗

Crimean-Congo hemorrhagic fever in Albania, 2001.

During the spring and summer of 2001, an outbreak of eight cases of Crimean-Congo hemorrhagic fever (CCHF) occurred in Albania. The epidemiological investigation, the clinical presentation of the cases, and the course of the disease are described. Seven of the cases were laboratory confirmed. A nosocomial infection and a cluster of cases within a family were observed. Genetic analysis of the CCHF virus strain that caused the outbreak showed that it was clustered together with other European CCHF virus strains except the Greek one (strain AP92). The Greek strain, which forms an independent clade, differed from the causative strain by 25.3% at the nucleotide level.

Adult↗

Functional capacity of the thyroid autograft: an experimental study.

BACKGROUND: The aim of this study was to investigate the functional capacity of thyroid autografts after total thyroidectomy in a rabbit model. MATERIAL AND METHODS: Thirty-eight rabbits underwent total thyroidetomy. One of the two thyroid lobes was cut into 1-mm pieces and was introduced intramuscularly into the right quadriceps muscle (group A, n = 10), the right rectus abdominalis muscle (group B, n = 10), and the right sacrodorsalis muscle (group C, n = 10). Another group of 8 rabbits underwent total thyroidectomy without autologous implantation and served as the control group (group D). The animals were observed for 8 weeks with weekly measurements of thyroid hormones. At the end of the 8th week, a scintigram was performed. The autografts were removed 2 days later. RESULTS: The thyroid hormone levels showed a gradual decrease until the 2nd-5th week after implantation, followed by a gradual increase and establishment of euthyroid levels between the 5th and 8th weeks. Respectively, an increase of thyreotropin hormone was noted with maximal values in the 4th week, followed by a gradual decrease until the end of the 8th week. The scintigram at the end of the 8th week revealed the presence of functional thyroid tissue in all cases. Functional thyroid follicles were found in all animals who survived. In 35.7% of the autografts, we noted the development of fibrous tissue and gigantocytic granulomas in the periphery, which could be interpretated as a "foreign body" reaction. CONCLUSION: Thyroid autografts can completely substitute thyroid function after total thyroidectomy.

Animals↗

Prevalence of Rickettsia conorii and Rickettsia typhi infections in the population of northern Greece.

Seroepidemical surveys concerning the prevalence of Rickettsia conorii and Rickettsia typhi have never been studied in northern Greece. We examined 1,584 sera samples from residents of northern Greece for the detection of antibodies to R. conorii and to R. typhi by means of immunofluorescence assay. In addition, we compared the prevalence of rickettsial infections among the demographic variables of sex, age, occupation, and area of residence. Antibodies to R. conorii and R. typhi were found in 125 (7.9%) and 31 (2.0%) of the examined subjects, respectively. The prevalence of antibodies to R. conorii correlated with increasing age and was statistically higher in men. Farmers had significantly higher prevalence of antibodies to both species of rickettsiae studied versus other professions. Residents of rural areas showed a statistically higher prevalence for R. conorii versus urban residents, although this difference was not demonstrated for R. typhi. We also detected differences in the prevalence of rickettsial infections among the different prefectures. Our data show the wide distribution of R. conorii in northern Greece and indicate the presence of R. typhi.

Adolescent↗

Outbreak of meningococcal disease after an influenza B epidemic at a Hellenic Air Force recruit training center.

In January 1996, during an outbreak of meningococcal disease at a Hellenic Air Force recruit center in southern Greece, we collected paired serum specimens from 55 randomly selected recruits and tested for antibodies against influenza virus types A and B. Of 55 specimens, 15 (27%) were found to be positive for recent influenza B infection, confirming previous reports that respiratory tract infection due to influenza is probably a predisposing factor for meningococcal disease.

Antibodies, Viral↗

Hantavirus infections in Greece--an update.

Hantaviruses are emerging viruses spread worldwide and cause hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Two pathogenic hantaviruses are present in Greece: Dobrava/Belgrade virus (DOBV) and Puumala virus (PUUV). The predominant one is DOBV, carried in Greece by the rodent Apodemus flavicollis. Most human infections are sporadic, but epidemic outbreaks were also described. The severity of the disease ranges from a mild or moderate form to severe and fatal cases. Several endemic foci for HFRS have been identified. Phylogenetic analysis of hantavirus sequences revealed a stable geographical distribution.

Animals↗