Analysis of emergence of quinolone-resistant gonococci in Greece by combined use of Neisseria gonorrhoeae multiantigen sequence typing and multilocus sequence typing

The prevalence of quinolone-resistant Neisseria gonorrhoeae (QRNG) in Greece remained low from 1997 to 2003 but increased dramatically from 11% to 56% between 2004 and 2007. N. gonorrhoeae multiantigen sequence typing (NG-MAST) and multilocus sequence typing (MLST) were used to investigate trends in quinolone resistance from 1997 to 2007 and explore the origins of the recent increase in QRNG. We characterized 295 QRNG isolates from the study period and 233 quinolone-susceptible (QS) gonococci from 2004 and 2005, when the rapid increase in QRNG occurred. From 1997 to 1999, an outbreak of QRNG was due to the dissemination of isolates of serovar Arst that belonged to two closely related genotypes. Few QRNG isolates, of diverse genotypes, were present between 2001 and 2003, whereas the sharp increase in QRNG from 2004 onwards was due to the appearance of serovar Bropyst isolates of several major NG-MAST sequence type (STs) that previously had not been identified in Greece. These isolates were shown by MLST to be variants of a single multiply antibiotic-resistant QRNG strain (ST1901) that appeared in Greece and rapidly diversified into 31 NG-MAST STs. There were no isolates of MLST ST1901 or any of the 31 NG-MAST STs among QS isolates from 2004 and 2005 or among 8 representatives of multiresistant but quinolone-susceptible serovar Bropyst isolates circulating in Greece during the 1990 s, supporting the view that the recent increase in QRNG was due to importation of a QRNG strain(s) of MLST ST1901 into Greece. Recently, multiresistant QRNG isolates of ST1901 with reduced susceptibility to the newer cephalosporins have appeared in Greece.     

Structural and Optical Properties of Polyhydrosilanes

This work presents a study of the optical properties of polyhydrosilanes in relation with their specific chemical structure. For this purpose, poly[methyl(H)silane‐co‐diphenylsilane] copolymers with a different content of methylhydrosilyl‐segments have been investigated. Steady‐state fluorescence analysis and X‐ray photoelectron spectrometry showed that polyhydrosilanes possess a specific emission profile due to the presence of both methylhydrosilyl segments and silicon nanoparticles within the polymeric matrix. Polyhydrosilanes are capable of generating singlet oxygen reactive species at room temperature. This unusual property was investigated by analyzing the morphological changes in biological systems during Hek293 cell cultures growth in the presence of polyhydrosilanes.

     

Moya moya syndrome in a child with pyruvate kinase deficiency and combined prothrombotic factors

A 13-year-old Greek girl with pyruvate kinase deficiency and moya moya angiographic pattern is reported. She also had raised serum lipoprotein (a) concentration and was homozygous for the C677T mutation of the methylenetetrahydrofolate reductase gene. She presented with neonatal onset of anemia, hemolytic and aplastic crises, especially during infections, stroke, and also progressive motor and mental deterioration. A digital cranial angiography at 13 years revealed the typical angiographic findings of moya moya angiopathy. This is likely the first patient with pyruvate kinase deficiency and moya moya syndrome and also the combination of elevated serum lipoprotein (a) concentration and the C677T mutation of the methylenetetrahydrofolate reductase gene to be reported. In patients with pyruvate kinase deficiency and moya moya syndrome, a search for raised serum lipoprotein (a) concentrations and the C677T mutation of the methylenetetrahydrofolate reductase gene should be considered.     

Synchronous neural interactions assessed by magnetoencephalography: a functional biomarker for brain disorders

We report on a test to assess the dynamic brain function at high temporal resolution using magnetoencephalography (MEG). The essence of the test is the measurement of the dynamic synchronous neural interactions, an essential aspect of the brain function. MEG signals were recorded from 248 axial gradiometers while 142 human subjects fixated a spot of light for 45-60 s. After fitting an autoregressive integrative moving average (ARIMA) model and taking the stationary residuals, all pairwise, zero-lag, partial cross-correlations (PCC(ij)(0)) and their z-transforms (z(ij)(0)) between i and j sensors were calculated, providing estimates of the strength and sign (positive, negative) of direct synchronous coupling at 1 ms temporal resolution. We found that subsets of z(ij)(0) successfully classified individual subjects to their respective groups (multiple sclerosis, Alzheimer's disease, schizophrenia, Sj?gren's syndrome, chronic alcoholism, facial pain, healthy controls) and gave excellent external cross-validation results.     

Comparative immunohistochemical analysis of aurora-A and aurora-B expression in human glioblastomas. Associations with proliferative activity and clinicopathological features

In the present study, we carried out a comparative immunohistochemical analysis of aurora-A and aurora-B expression in 40 patients with primary glioblastomas, and attempted to identify any associations with Ki-67 index and the patients’ clinical features. The impact of various treatment modalities and proliferative activity on patient outcome was also assessed.Immunohistochemistry was carried out using formalin-fixed and paraffin-embedded tissue sections.Aurora-A expression was higher in tumors with high Ki-67 expression (p=0.01) and was positively, though marginally, related to aurora-B expression (p=0.085). Aurora-B expression was not linked to Ki-67 expression (p=0.182). Lower aurora-A immunohistochemical expression, chemotherapy administration, and tumor localization in one lobe of the brain implied a greater probability of patient survival in univariate analysis (p=0.044, p=0.008, p=0.041, respectively). Ki-67 and aurora-B immunoreactivities were not associated with patient survival (p=0.918 and p=0.539, respectively).To our knowledge, for the first time, the association between aurora-A and aurora-B expression, the correlation of aurora-A with Ki-67 index, and the prognostic impact of aurora-A expression were assessed in glioblastomas. Although we addressed a prognostic connotation of aurora-A, we presume that aurora-A and aurora-B play a complicated role within glioblastomas. Further examinations of larger series are required, so that definite conclusions can be drawn.     

Age-Related Changes in Regional Brain Activation During Phonological Decoding and Printed Word Recognition

Using magnetic source imaging, age-related changes in spatiotemporal brain activation profiles associated with printed word recognition and phonological decoding (pseudoword reading) were examined in 27 adults and 22 children without reading problems. Adults showed a distinct spatiotemporal profile during reading of both types of print consisting of bilateral activation of occipital cortices, followed by strongly left-predominant activation of basal temporal regions, and, finally, left hemisphere temporoparietal (including the angular gyrus) and inferior frontal activation. Children lacked the clear temporal distinction in the engagement of basal and temporoparietal areas and displayed significantly weaker activation of the left inferior frontal gyrus. In addition, the consistent hemispheric asymmetries in the degree of activation of basal temporal regions that were present in the adult readers were not apparent in the children. In contrast, the strong left hemisphere preponderance in the degree of activation of temporoparietal areas was present in children as well as adults, regardless of the type of print they were asked to read. The data suggest that the degree of specialization of cortical regions for reading, as well as the pattern of regional interactions that supports this specialization, may change with age.